Max Heart Rate Calculator – Your Ceiling, From Four Formulas, Not One Guess
Your maximum heart rate quietly sets every training zone you will ever use — and the famous 220 minus age shortcut is the roughest way to find it. This page runs your age through four published formulas — Fox, Tanaka, Gulati and HUNT — shows you where they agree and where they argue, then turns the result into your five training zones: by plain percentages, or by the Karvonen heart-rate-reserve method if you add your resting heart rate.
Your details
🔒 Private by design: the whole calculation runs in this page. Your numbers are never sent anywhere.
Your estimated maximum heart rate
For a 40-year-old woman, the four published formulas put the maximum between 171 and 185 bpm. Tanaka (2001) is the primary estimate on this page — the most broadly validated of the four.
Primary estimate: Tanaka 208 − 0.7 × ageHow your zones were built
Four formulas, one honest spread
No age formula knows your heart — each one averages thousands of strangers. Treat the gap between the lowest and highest estimate as the real size of the uncertainty, set your zones from the primary estimate, then calibrate by feel over the first weeks: if Zone 2 leaves you unable to finish a sentence, your true maximum is probably lower than the estimate; if Zone 4 feels like a cruise, it is probably higher.
Method: Tanaka and colleagues (2001) as the primary estimate; Fox (1971), Gulati and colleagues (2010, women) and the HUNT study (Nes and colleagues, 2013) shown for comparison. Every formula estimates a population average — your own maximum can sit 10 to 12 bpm either side of it.
- Four published lines, one age: at 40 they span 14 beats, from Gulati’s 171 to HUNT’s 185 — where they cluster is your likely ceiling, and how far apart they sit is the honest uncertainty.
- Fox and Tanaka agree exactly at 40 by algebra (220 − age = 208 − 0.7 × age); below 40 Fox reads higher, above 40 lower, drifting 0.3 beats wider every year past 40.
- Add a resting rate and the zones rebuild by Karvonen — rest + intensity × (maximum − rest) — counting only the beats between resting and maximum, so every zone sits a little higher.
- Your five training zones
- How your maximum is worked out, in three steps
- The formulas, and every assumption in the open
- Going deeper
- Four formulas, one age: the 14-beat spread at 40
- The crossover at 40, and the drift after it
- Karvonen: zones from where your heart idles
- Why the poster, the watch and this page disagree
- How to measure your real maximum: the field test
- At the edges of the chart: children, older adults, heart conditions
- Frequently asked questions
Your five training zones
Zones are slices of your maximum, each with a job. The table below is drawn from the primary Tanaka estimate. Enter a resting heart rate above and the same five zones are rebuilt with the Karvonen method — which counts only the beats between your resting rate and your maximum, so every zone sits a little higher and usually feels more honest.
| Zone | Intensity | Your range (bpm) | What it is for |
|---|---|---|---|
| Zone 1 — Recovery | 50–60% | 90–108 | Warm-ups, cool-downs and gentle recovery days. Full conversation, no strain. |
| Zone 2 — Endurance base | 60–70% | 108–126 | The fat-burning base. Steady breathing, easy conversation — most of your weekly training time belongs here. |
| Zone 3 — Aerobic | 70–80% | 126–144 | Comfortably hard tempo work. Talking takes real effort; this is where aerobic fitness is built. |
| Zone 4 — Threshold | 80–90% | 144–162 | Near your lactate threshold. Only short phrases come out; sustainable for minutes, not hours. |
| Zone 5 — Maximum | 90–100% | 162–180 | All-out intervals in short bursts. Speaking is not happening — this is your ceiling. |
Plain percentage method — each zone is a straight slice of the Tanaka maximum. Add your resting heart rate in the calculator and these zones switch to the Karvonen heart-rate-reserve method.
The same zones from all four formulas
Four honest formulas, four slightly different ceilings — so the zones move too. This is why two calculators can hand the same person different Zone 2 ranges and both be defensible.
| Formula | Maximum (bpm) | Zone 2 (bpm) | Zone 4 (bpm) |
|---|---|---|---|
| Fox (1971) | 180 | 108–126 | 144–162 |
| Tanaka (2001) — primary | 180 | 108–126 | 144–162 |
| Gulati (2010) — women | 171 | 103–120 | 137–154 |
| HUNT (2013) | 185 | 111–130 | 148–167 |
The Gulati row is women-only: the equation was derived from 5,437 asymptomatic women (Gulati and colleagues, 2010), because the older formulas systematically overshot what women actually reached in testing.
Keep exploring
VO2 Max Calculator
The other half of the engine: how much oxygen you can actually use when your heart is near this ceiling.
🔥TDEE Calculator
Training in these zones burns fuel — see your total daily energy expenditure from the same activity.
⏱️Running Pace Calculator
Turn your test times into pace per mile or kilometre, and project finish times for your next race distance.
How your maximum is worked out, in three steps
Enter your age
Age is the only input every formula shares. Sex adds one more formula to the comparison — Gulati, built from women — and nothing else about you is needed.
Run four formulas
Fox, Tanaka, Gulati and HUNT each draw a different line through real measured data. Where they cluster is your likely ceiling; how far apart they sit is the honest uncertainty.
Slice it into zones
The primary estimate is cut into the five standard zones. Add your resting heart rate and the slicing switches to Karvonen, which starts counting from where your heart idles, not from zero.
The formulas, and every assumption in the open
Here is the default example on this page, worked in full — a 40-year-old woman, all four formulas:
| Formula | Working | Maximum |
|---|---|---|
| Fox (1971) | 220 − 40 | 180 bpm |
| Tanaka (2001) | 208 − 0.7 × 40 = 208 − 28.0 | 180 bpm |
| Gulati (2010) | 206 − 0.88 × 40 = 206 − 35.2 | 171 bpm |
| HUNT (2013) | 211 − 0.64 × 40 = 211 − 25.6 | 185 bpm |
The spread at age 40 is 14 beats, from Gulati’s 171 to HUNT’s 185, with Fox and Tanaka agreeing exactly in the middle. And the Karvonen twist, with a resting rate of 60 against the Tanaka maximum of 180: the reserve is 180 − 60 = 120 beats, so Zone 3 runs from 60 + 70% × 120 = 144 to 60 + 80% × 120 = 156 — higher than the plain-percentage 126 to 144, because Karvonen starts counting from your resting rate rather than from zero.
Why the gym poster and your watch disagree with this page
The poster on the gym wall uses Fox alone, rounded into tidy decades. Your watch does something else entirely: it watches your training, takes the highest heart rate it has actually seen (or models one), and calls that your maximum — which is why it creeps upward the first time you race hard with it on. Neither is a measurement. The only true maximum comes from a maximal test: a graded effort to genuine exhaustion with a chest strap recording. Until then, every number — this page’s included — is an estimate wearing different clothes, and disagreements of 5 to 15 beats between sources are normal, not a sign that one of them is broken.
Assumptions, printed rather than buried
- Tanaka is the primary estimate because its 2001 meta-analysis — 351 studies, 18,712 people — is the most broadly validated general formula. Primary means “best single guess”, not “true”.
- Zones are worked out from the rounded maximum printed at the top of the results, so the headline number and every zone boundary on this page always agree with each other.
- Gulati appears only for women. It was derived from 5,437 asymptomatic women; applying it to men would borrow a line fitted to a different population.
- Karvonen zones on this page always build on the Tanaka maximum. The method changes where counting starts — your resting rate — not which maximum is used.
- Individual variation is the big caveat. Within any age group, true maxima commonly sit 10 to 12 bpm either side of every formula’s line. Roughly a third of people land further out than that.
- Medication changes the answer. Beta blockers and some other medicines lower the achievable maximum by roughly 20 to 30 bpm and flatten the response; formula zones built without that knowledge will overshoot. Perceived exertion and the talk test serve you better there.
- Accepted ranges: age 5 to 100, resting heart rate 30 to 120 bpm. A resting rate entered above the estimated maximum is rejected, because the reserve it implies does not exist.
Going deeper
The oldest line on this page was almost an aside. In 1971, Fox, Naughton and Haskell reviewed the available studies of physical activity and coronary heart disease and noted that maximum heart rate fell at roughly one beat per year of age — the observation that hardened into 220 minus age. The samples behind it were small, mostly young and mostly male, and the authors never presented the line as a precision instrument. Fifty years of gym posters did that part themselves.
The correction arrived in 2001, when Tanaka, Monahan and Seals published a meta-analysis in the Journal of the American College of Cardiology covering 351 studies and 18,712 subjects, backed by their own laboratory study of 514 people. Their regression — 208 minus 0.7 times age — fit the measured data across the whole adult span far better than Fox, especially past 40, where Fox drifts increasingly low. It remains the most-cited general equation in the field.
Gulati’s line exists because the older formulas were fitted mostly to men. In 2010, Gulati and colleagues reported in Circulation on 5,437 asymptomatic women who had taken exercise stress tests: the women’s actual peak heart rates followed 206 minus 0.88 times age, and the traditional formula misclassified a large share of them. It was the first widely adopted sex-specific equation. The HUNT line, finally, comes from the Nord-Trøndelag Health Study in Norway: Nes and colleagues (2013) measured 3,320 healthy adults aged 19 to 89 and fitted 211 minus 0.64 times age — the shallowest slope of the four, which is why it reads highest at older ages.
If the zones matter enough — a race season, a coached programme — a field test beats every formula here. The usual shape: a thorough warm-up, then a graded run or ride that steps up every couple of minutes until you genuinely cannot hold the pace, wearing a chest strap (wrist sensors lag and drop beats at the top end). The highest sustained reading is close to your true maximum. It is also, by definition, a maximal effort: anyone with a heart condition, symptoms, or medical advice against maximal exercise should treat the formulas as the end of the road, not a starting point.
Most people, though, train perfectly well on estimates — provided they cross-check them against the two instruments built into the body. The talk test: in Zone 2 you can speak in full sentences; in Zone 4 you cannot get out more than a few words. Perceived exertion: Zone 3 feels comfortably hard, Zone 5 feels like the last interval of the hardest session of the month. When the zones and those signals disagree week after week, believe the signals and nudge the assumed maximum five beats in the direction they point. A maximum that is ten beats wrong shifts every zone by up to ten beats too — Zone 2 quietly becomes Zone 3 — which is why the calibration step, not the formula choice, is where accurate training zones are really made.
Four formulas, one age: the 14-beat spread at 40
Age is the only input every formula shares, and at 40 the four published lines do not agree — they span 14 beats. The table below is the page’s own comparison table for a 40-year-old woman, with the workings from the formulas section, and the zone columns show why the spread matters: the same Zone 2 workout is prescribed at different heart rates depending on which ceiling you start from.
| Formula | Working at age 40 | Maximum | Zone 2 | Zone 4 |
|---|---|---|---|---|
| Fox (1971) | 220 − 40 | 180 bpm | 108–126 | 144–162 |
| Tanaka (2001) — primary | 208 − 0.7 × 40 = 208 − 28.0 | 180 bpm | 108–126 | 144–162 |
| Gulati (2010) — women | 206 − 0.88 × 40 = 206 − 35.2 | 171 bpm | 103–120 | 137–154 |
| HUNT (2013) | 211 − 0.64 × 40 = 211 − 25.6 | 185 bpm | 111–130 | 148–167 |
Where the formulas cluster is your likely ceiling; how far apart they sit is the honest uncertainty. Fox and Tanaka agree exactly in the middle at 180, Gulati sits 9 beats below them, and HUNT sits 5 above — and the zone columns translate that directly into training: Zone 2 runs 108 to 126 on the Fox and Tanaka ceilings, 103 to 120 on Gulati’s, and 111 to 130 on HUNT’s. That is why two calculators can hand the same person different Zone 2 ranges and both be defensible — they started from different ceilings. Tanaka is the primary estimate because its 2001 meta-analysis, covering 351 studies and 18,712 subjects and backed by the authors’ own laboratory study of 514 people, is the most broadly validated general equation. Gulati’s line exists because the older formulas were fitted mostly to men: in 2010, Gulati and colleagues reported in Circulation on 5,437 asymptomatic women who had taken exercise stress tests, and the women’s actual peak heart rates followed 206 minus 0.88 times age. The Gulati row is women-only, and for a man at 40 the published range on this page is 180 to 185 — Fox, Tanaka and HUNT alone.
The crossover at 40, and the drift after it
Fox and Tanaka agree exactly at 40, and that is not a coincidence — it is algebra. Fox falls one beat per year of age; Tanaka falls 0.7 beats per year. Set them equal — 220 minus age equals 208 minus 0.7 times age — and the solution is age 40. Below 40, Fox reads higher; above 40, Fox reads lower, and the gap grows by 0.3 beats with every year past 40. The calculator confirms the drift at both ends, for a woman: at 20, the published formulas put the maximum between 188 and 200 bpm, with Tanaka at 194; at 60, between 153 and 173 bpm, with Tanaka at 166. Every figure in the table below follows the four printed formulas, with the age-20 and age-60 rows produced by the calculator itself.
| Age (woman) | Fox | Tanaka (primary) | Gulati | HUNT | Spread |
|---|---|---|---|---|---|
| 20 | 200 | 194 | 188 | 198 | 12 beats |
| 40 | 180 | 180 | 171 | 185 | 14 beats |
| 60 | 160 | 166 | 153 | 173 | 20 beats |
Three lessons sit in that table. First, the spread widens with age — from 12 beats at 20 to 20 beats at 60 — because the slopes differ: the shallowest line, HUNT at 0.64 beats per year, reads highest at older ages, while the steepest, Fox at a full beat per year, falls fastest. Second, Fox’s error grows with age in a known direction: past 60 it systematically underestimates what most people reach, which is why the page calls Fox the oldest and roughest of the four, never designed as an individual predictor, with measured maxima scattering around it with a standard error of roughly 10 to 12 beats per minute. Third, the individual scatter dwarfs the formula spread: healthy individuals of the same age routinely sit 10 to 12 beats either side of every one of those lines. The formulas give you the neighbourhood; your own maximum lives somewhere inside it, and only a maximal test finds the exact address.
Karvonen: zones from where your heart idles
Enter a resting heart rate and the same five zones are rebuilt with the Karvonen method — which counts only the beats between your resting rate and your maximum, so every zone sits a little higher and usually feels more honest. The formula is: target equals rest plus intensity times (maximum minus rest). On the defaults — a 40-year-old woman, Tanaka maximum 180 — with a resting rate of 60, the reserve is 180 minus 60, which is 120 beats. The table below shows the plain-percentage zones beside the Karvonen zones, with the Karvonen rows produced by the calculator itself.
| Zone | Plain percentage (of 180) | Karvonen, rest 60 (reserve 120) | Karvonen, rest 80 (reserve 100) |
|---|---|---|---|
| Zone 1 — Recovery (50–60%) | 90–108 | 120–132 | 130–140 |
| Zone 2 — Endurance base (60–70%) | 108–126 | 132–144 | 140–150 |
| Zone 3 — Aerobic (70–80%) | 126–144 | 144–156 | 150–160 |
| Zone 4 — Threshold (80–90%) | 144–162 | 156–168 | 160–170 |
| Zone 5 — Maximum (90–100%) | 162–180 | 168–180 | 170–180 |
Every Karvonen zone sits higher than its plain-percentage twin, because Karvonen starts counting from where your heart idles rather than from zero. The page’s own worked example is Zone 3 at rest 60: 60 plus 70% of 120 is 144, to 60 plus 80% of 120, which is 156 — against the plain 126 to 144. The higher the resting rate, the higher the zones climb: at rest 80, Zone 2 runs 140 to 150, a full 32 beats above the plain 108 to 126 at its lower edge. If the two methods disagree about a workout, Karvonen is usually the better mirror of how the effort actually feels, because it knows where your heart starts the day — which is also why the resting rate must be a true resting rate, taken at rest, not after coffee, a walk, or a stressful morning. A resting rate entered 10 beats too high lifts every zone by 3 to 5 beats, since only the reserve fraction of the error survives: at 60% intensity, 10 extra resting beats move the zone edge by 4 beats, not 10.
Why the poster, the watch and this page disagree
The poster on the gym wall uses Fox alone, rounded into tidy decades. Your watch does something else entirely: it watches your training, takes the highest heart rate it has actually seen (or models one), and calls that your maximum — which is why it creeps upward the first time you race hard with it on. Neither is a measurement. The only true maximum comes from a maximal test: a graded effort to genuine exhaustion with a chest strap recording. Until then, every number — this page’s included — is an estimate wearing different clothes, and disagreements of 5 to 15 beats between sources are normal, not a sign that one of them is broken.
That framing also answers the question every lifter and runner eventually asks: is a higher maximum better? Maximum heart rate is mostly inherited and age-driven; a lower number than your training partner’s does not mean a weaker heart, and a higher one is not a fitness trophy. What coaches actually use the number for is setting zones, and for that, landing in the right neighbourhood is enough. If the zones matter enough — a race season, a coached programme — a field test beats every formula, and two or three weeks of training with the talk test will tell you more about your true maximum than any formula: Zone 2 should allow easy conversation, Zone 3 should make talking take real effort, Zone 4 should reduce you to short phrases, and Zone 5 should make speaking not happen at all. When the talk test and the formula disagree, trust the talk test for the session and the formula for the plan — and revisit both after a few weeks of consistent training, because fitness moves the zones’ feel long before it moves the ceiling itself.
How to measure your real maximum: the field test
A hard effort test beats any formula, if you do it safely.
Warm up for 10 to 15 minutes at an easy effort, then build to hard work in steps: either three hard efforts of about three minutes each with short recoveries, or a steady ramp that ends all-out over the last minutes. Take the highest number your watch or chest strap shows across the hard efforts: that is your measured maximum, and it replaces the formula for your zones. The test only counts if you truly went all-out, which is why it is best done when rested, on a familiar route or machine, and not the day after a hard session.
Stop at once for chest pain, dizziness, unusual breathlessness, or any symptom that feels wrong, and see a doctor before testing if you are over 40 and sedentary, have a known heart condition, or take heart medication. A field test is general fitness information, not a medical test, and it does not replace medical advice. Repeat the test after a training block if your zones start to feel too easy: fitness moves the feel of the zones long before it moves the ceiling itself.
At the edges of the chart: children, older adults, heart conditions
The formulas were fitted to healthy adults, and the edges are where they break.
Children are the clearest edge: the formulas on this page were derived from adult data, and they were not designed for children, whose maxima are higher and change less steeply with age. Do not use an adult formula to set a child’s training zones. Older adults are the second edge: the ceiling still falls with age, but individual variation widens, so a formula that is within a few beats for a typical 40-year-old can be much further off for a 70-year-old, and a measured maximum matters more, not less. Heart conditions and heart medications are the third edge: beta blockers and similar drugs lower the maximum directly, so formula zones built on an unmedicated maximum are simply wrong for someone taking them, and zones should come from a clinician or a measured test instead.
Frequently asked questions
What is a normal maximum heart rate for my age?
There is no single normal — there is a normal neighbourhood. At age 40, the four published formulas on this page put the average maximum between 171 and 185 bpm, and healthy individuals of the same age routinely sit 10 to 12 beats either side of every one of those lines. Maximum heart rate is mostly inherited and age-driven; a lower number than your training partner’s does not mean a weaker heart, and a higher one is not a fitness trophy. What coaches actually use the number for is setting zones, and for that, landing in the right neighbourhood is enough.
How accurate is the 220 minus age formula?
It is the oldest and roughest of the four. Fox’s line came from a 1971 review of small studies, mostly of young men, and it was never designed as an individual predictor: measured maxima scatter around it with a standard error of roughly 10 to 12 bpm, and the error grows with age — past 60 it systematically underestimates what most people reach. At 40 it happens to agree with the modern Tanaka formula almost exactly, which is why it survives. For a quick guess it is fine; for setting training zones, Tanaka, Gulati or HUNT will serve you better.
Which formula should I use?
Start with Tanaka — it was fitted to the largest dataset (351 studies, 18,712 people) and is the primary estimate on this page. If you are a woman, compare it with Gulati, which was derived from women alone and often lands a few beats lower; if the two bracket your experience, train to the one whose zones feel right. HUNT tends to read highest, especially at older ages. But treat the choice as a starting point, not a verdict: two or three weeks of training with the talk test will tell you more about your true maximum than any formula can.
What is the Karvonen method?
Karvonen builds zones from your heart-rate reserve — the gap between your resting heart rate and your maximum — instead of from zero. The target for an intensity is resting rate plus that percentage of the reserve: with a maximum of 180 and a resting rate of 60, the reserve is 120 beats, and 70 percent of it gives 60 + 84 = 144 bpm. Because it knows where your heart starts the day, Karvonen zones sit higher than plain percentages and usually match perceived effort better, especially for fit people with low resting rates. Enter your resting heart rate in the calculator and every zone on this page switches to Karvonen.
Can I raise my maximum heart rate with training?
Essentially, no — and that is not bad news. Maximum heart rate is set mostly by age and genetics and drifts down by roughly 0.7 to 1 beat per year whatever you do; training has, at most, a few beats of influence on it. What training transforms is everything below the ceiling: you produce more power at the same heart rate, your resting rate falls, and you recover faster between efforts. A falling resting rate alongside a stable maximum is exactly what getting fitter looks like on paper — the reserve between them is what Karvonen zones spend.
I take beta blockers. Do these zones apply to me?
Not cleanly, no. Beta blockers commonly lower the heart rate you can actually reach by roughly 20 to 30 bpm and flatten the whole response, so zones computed from age formulas point at intensities your heart, on that medication, cannot and should not chase. The honest tools in that situation are perceived exertion and the talk test — Zone 2 is the effort where full sentences stay comfortable — backed by your clinician’s guidance. The same caution applies to anyone with a heart condition or symptoms during exercise: the formulas describe averages of healthy study volunteers, not instructions for you.
Why do Fox and Tanaka agree exactly at my age?
Because 40 is where their lines cross. Fox falls one beat per year of age; Tanaka falls 0.7 beats per year. Set them equal — 220 minus age equals 208 minus 0.7 times age — and the solution is age 40, where both give 180. Below 40, Fox reads higher: at 20, Fox gives 200 against Tanaka’s 194. Above 40, Fox reads lower, and the gap grows by 0.3 beats with every year past 40: at 60, Fox gives 160 against Tanaka’s 166. If the two agree for you, you are near the crossover, not holding a special confirmation — and past 60, Fox systematically underestimates what most people reach.
I entered a resting heart rate. Why did all my zones move up?
Because the slicing switched to the Karvonen method, which counts only the beats between your resting rate and your maximum. With a Tanaka maximum of 180 and a resting rate of 60, the reserve is 120 beats, so Zone 3 runs from 60 plus 70% of 120, which is 144, to 60 plus 80% of 120, which is 156 — against the plain-percentage 126 to 144. Every zone sits higher, because Karvonen starts counting from where your heart idles rather than from zero. If the two methods disagree about a workout, Karvonen is usually the better mirror of how the effort actually feels — provided the resting rate you entered was a true resting rate.
My watch says my max is 195 at age 40. Is the page wrong?
Not necessarily — and neither is the watch. At 40, the four published formulas put the average maximum between 171 and 185 bpm, and healthy individuals of the same age routinely sit 10 to 12 beats either side of every one of those lines, so 195 is outside the formula neighbourhood but not outside human variation. Your watch takes the highest heart rate it has actually seen, or models one, and calls that your maximum. The only true maximum comes from a maximal test: a graded effort to genuine exhaustion with a chest strap recording. Disagreements of 5 to 15 beats between sources are normal, not a sign that one of them is broken.
Should a man use the Gulati formula?
No. Gulati’s line was derived from 5,437 asymptomatic women who had taken exercise stress tests, and it was the first widely adopted sex-specific equation precisely because the older formulas had been fitted mostly to men. The Gulati row is women-only: at 40 it gives 171 bpm, 9 beats below the Fox and Tanaka agreement at 180. For a man at 40, the published range on this page is 180 to 185 — Fox, Tanaka and HUNT alone. If you are a woman, compare Tanaka with Gulati, and if the two bracket your experience, train to the one whose zones feel right.
Can my real maximum be higher than the formula says?
Yes, by 10 to 12 beats per minute or more. A formula predicts the average maximum for people of your age, and individuals scatter widely around that average: the standard deviation of the Fox formula is about 10 to 12 beats, so a measured maximum well above the formula line is normal, not an error, and not a sign of a problem. If you have measured it in a genuine all-out effort, trust the measurement over the formula.
Is my watch maximum heart rate accurate?
A watch reports what it has observed, which is a lower bound unless you have truly gone all-out. Most watches take the highest rate recorded across workouts, sometimes blended with a formula, and they only see efforts you actually did: a watch that has never seen you sprint cannot know your maximum. Treat the watch figure as a working estimate that improves as you log harder efforts, and replace it with a field-test maximum when you have one.
Does maximum heart rate fall with age even if you stay fit?
Yes. The ceiling declines with age in every study, including studies of lifelong athletes: a fit 60-year-old has a higher maximum than a sedentary peer of the same age, but a lower maximum than their own younger self. What fitness preserves is not the ceiling but what you can sustain near it: a trained heart holds a high fraction of its maximum for longer, recovers faster, and rests lower, while the ceiling itself keeps its slow downward drift.
Related calculators
VO2 Max Calculator
How much oxygen your engine can use, from three field tests.
🔥TDEE Calculator
Total daily energy expenditure from your activity level.
⏱️Running Pace
Pace, time and distance for any run.
💪FFMI Calculator
Lean mass for your height, adjusted to a standard frame.
⚖️BMI Calculator
Body mass index from your weight and height.
❤️Maximum Heart Rate by Age
Chart and formula, ages 20 to 70.
🎯Target Heart Rate Zones
Five zones, Karvonen, and the talk test.
Built on the formulas of Fox (1971), Tanaka and colleagues (2001), Gulati and colleagues (2010) and the HUNT Fitness Study (Nes and colleagues, 2013) — because a number you cannot trace is a number you should not train by.
↑