Every protein target on this site is one multiplication: weight in kilograms times grams per kilogram per day. This guide shows how to choose the inputs to that multiplication, how to read the range that comes back, how to do the same arithmetic in pounds, and how to check the result with a pencil before you plan a single meal around it.

Start with the calculator, not with a number

Most searches for how much protein to eat are really asking for one number. The Protein Calculator on this site deliberately does not give one number. It gives a range, a chart, and a per-meal split, because the honest answer depends on three inputs you supply: your body weight, how active you are, and what your body is being asked to do. This guide explains how to use those inputs well, how to read the range that comes back, and how to check the answer by hand. The ranges used throughout are the calculator’s own ranges, stated in grams of protein per kilogram of body weight per day. Nothing in this guide adds a new figure to them; every worked number below is arithmetic on those ranges.

Enter your weight first, in pounds or kilograms. The calculator converts pounds to kilograms by dividing by 2.205, because the guidance is written per kilogram. Next, pick the activity level that matches your ordinary week, not your best week. Then pick your goal: maintain, lose weight, or gain muscle. The calculator multiplies your weight in kilograms by the range for your activity level, adjusts the aim for your goal, and divides the daily total by the number of meals you choose, so you get grams per day and grams per meal. The chart shows the low end of the range in green and the high end in orange. Anywhere inside that zone is a defensible aim; the goal tells you which part of the zone to favour, as the next sections explain.

Picking your activity level

The calculator offers five activity levels, and the choice matters more than most people expect. The ranges are: sedentary 1.2 to 1.6 grams per kilogram per day, light 1.4 to 1.8, moderate 1.6 to 2.0, active 1.6 to 2.2, and athlete 2.0 to 2.4. Pick by what your body does across a normal week. Sedentary means a desk job and little planned exercise. Light means some walking or light activity most days. Moderate means regular training a few times a week. Active means hard training most days. Athlete means competitive training or heavy resistance work. If you are between two levels, pick the lower one first and read the range it gives; you can always re-run the calculator at the higher level and compare the two ranges before deciding.

The cost of picking wrong is easy to size. At 80 kg, the sedentary range is 96 to 128 grams a day, the moderate range is 128 to 160 grams, and the athlete range is 160 to 192 grams. Choosing the athlete range for a sedentary week overshoots the sedentary range by 64 grams at the top end, roughly a whole extra meal of protein every day. Choosing the sedentary range while training hard undershoots by the same kind of margin. The table below shows all five levels at 80 kg so the step between levels can be seen at a glance.

Ranges are the Protein Calculator’s own. The moderate row is highlighted because it is the middle of the five levels, not because it suits everyone.

Two cautions belong here. First, activity is not a badge. A week with one hard workout and six desk days is not an athlete week, and the calculator has no way to know that unless you tell it honestly. Second, activity and goal are separate inputs. Training hard does not by itself mean you should use the gain range; the gain adjustment is for building muscle, and it is covered in the companion guide on protein by goal. Keep the two choices apart: activity describes the week you already live, goal describes what you want the protein to do.

The per-pound shortcut

Readers who think in pounds often want the same arithmetic without converting to kilograms first. It can be done, by dividing each grams-per-kilogram figure by 2.205, the same divisor the calculator uses for the weight conversion. The result is grams of protein per pound of body weight per day. The shortcut is exact arithmetic on the same ranges, but it introduces rounding: a per-pound figure carried to only two decimal places, then multiplied by a large weight, can drift by a gram or two from the kilogram calculation. Use the shortcut for quick estimates and the kilogram multiplication for the number you actually plan around.

Grams per pound are the grams-per-kilogram ranges divided by 2.205, rounded to two decimal places. Daily targets are computed from kilograms, as the calculator does.

One round number deserves a mention because it is the calculator’s own rule of thumb, not a new figure: the lean-mass target sizes protein at 2.2 grams per kilogram of lean mass, which is about 1 gram per pound of lean mass. Lean mass is total weight minus fat mass, so the rule needs a body-fat percentage to use. If you do not know yours, use total body weight and the ranges above. The lean-mass variant is most useful for lean, muscular builds, where total-weight ranges can undershoot, and for very heavy adults, where they can overshoot because fat tissue needs little protein.

Reading a range: low end, high end, and where to aim

A range is not a failure to decide. Guidance comes out as a band because studies measure groups, not individuals, and a band is the honest form for advice that must fit many bodies. The low end of your range is the smallest daily total the calculator considers adequate for your activity level. The high end is the largest total it considers useful before extra protein mainly adds calories. The floor of about 0.8 grams per kilogram sits below every range on the calculator; it is the minimum to avoid deficiency for a sedentary adult, not a target for anyone training or dieting. At 70 kg it is 56 grams a day, against 112 to 154 grams for an active person at the same weight. Do not aim at the floor unless a clinician has told you to.

Where inside the range to aim is decided by your goal. Maintaining follows activity alone: any point in the range is consistent with the goal, and the middle is a reasonable starting aim. Losing weight aims at the top of the range, because higher protein helps protect muscle while calories are low. Gaining muscle uses a raised range, 1.8 to 2.4 grams per kilogram, so both the floor and the ceiling move up. The size of the goal effect is worth stating plainly: at 80 kg, each 0.2 grams per kilogram is 16 grams a day, roughly one protein anchor at one meal, every day. Goals are not rounding errors. How the goal changes the target, weight by weight, is the subject of the companion guide Protein for Muscle Gain and Weight Loss.

Once you have a daily total, the per-meal split is simple division. A 112 to 154 gram day is 37 to 51 grams at three meals, 28 to 38 grams at four, and 22 to 31 grams at five, counting snacks as meals. The daily total matters most; the per-meal ceiling is soft, and a bigger meal is not wasted. The split mainly buys achievability: a daunting daily number becomes ordinary once it is divided across plates. The companion guide Daily Protein Intake and Per-Meal Targets works through the split in full, including how to hit it with real food, and it is listed in the related guides below.

Checking your answer by hand

Three checks, each taking seconds, catch nearly every wrong target. First, check the conversion: kilograms equal pounds divided by 2.205. 150 lb is 68.0 kg, 180 lb is 81.6 kg, 200 lb is 90.7 kg, and 250 lb is 113.4 kg. If your kilogram figure is larger than your pound figure, the units have been swapped. Second, check the multiplication: weight in kilograms times the range for your activity level. A 70 kg active person at 1.6 to 2.2 grams per kilogram lands at 112 to 154 grams a day; if the calculator shows something far from that for the same inputs, an input is wrong. Third, check the split: daily grams divided by meals. A total that does not divide cleanly into the per-meal figures shown is a sign the meals setting is not what you think it is.

Worked hand-check, start to finish. A reader weighing 165 lb, training moderately, maintaining weight: 165 divided by 2.205 is 74.8 kg. At the moderate range of 1.6 to 2.0 grams per kilogram, 74.8 times 1.6 is 119.7 grams and 74.8 times 2.0 is 149.7 grams, so the target is about 120 to 150 grams a day. Over three meals that is 40 to 50 grams per meal; over four, 30 to 37 grams. If the calculator shows 264 to 330 grams for this reader, pounds have been entered as kilograms. If it shows 90 to 113 grams, the sedentary range has been picked, or the goal has been set to lose weight with the wrong activity level. The check takes ten seconds and it catches the mistake that no amount of later care can undo.

When your inputs change

A protein target is a snapshot of a weight, an activity level, and a goal. When any of the three changes, the snapshot goes stale. Losing or gaining weight changes the multiplication directly: the same range applied to a lighter body gives a smaller total, and that is correct, not a reason to keep eating to the old number. Changing how much you train changes the range itself. Changing goal, from losing weight to maintaining, for example, moves the aim point back from the top of the range toward the middle, and the daily total falls even if weight and activity stay exactly the same. Re-enter your current weight, re-pick the activity level that matches your current week, and re-pick your current goal, and let the calculator do the multiplication again. Do not adjust the old target by feel; the whole point of the calculator is that the arithmetic is exact and the feeling is not.

One more change deserves a line of its own: the change from total weight to lean mass, or back. If you learn your body-fat percentage and switch to the lean-mass target, expect a different number, sometimes a larger one at the same total weight, because lean tissue is what the protein maintains. That is a change of method, not a correction of an error, and it should be made deliberately, once, with the new input recorded, rather than by drifting between methods from week to week. Consistency of method matters as much as the number itself: the same method, applied to current inputs, is what makes a target comparable over time.

All of this is general information for healthy adults. The ranges are population-level guidance, not personal advice, and they do not replace a clinician or a registered dietitian for anyone with a kidney condition, a medical diet, pregnancy, or a clinical nutrition plan. Used as intended, the method is deliberately boring: convert, multiply, divide by meals, and check by hand. Boring is the point. A target you can reproduce with a pencil is a target you can trust, adjust, and actually eat to.

Frequently asked questions

How do I choose my activity level on the Protein Calculator?

Choose the level that matches an ordinary week, not your best week: sedentary for a desk job with little planned exercise, light for some walking or light activity most days, moderate for regular training a few times a week, active for hard training most days, and athlete for competitive training or heavy resistance work. If you are between two levels, start with the lower one and compare the two ranges. At 80 kg the sedentary range is 96 to 128 grams a day and the athlete range is 160 to 192 grams, so the choice moves the target by tens of grams.

How much protein do I need per pound of body weight?

Divide the grams-per-kilogram range by 2.205. That gives 0.54 to 0.73 grams per pound for a sedentary adult, 0.73 to 0.91 for moderate activity, and 0.91 to 1.09 for athletes, per day. At 180 lb (81.6 kg) the moderate range is 131 to 163 grams a day. The per-pound figures are rounded, so use the kilogram multiplication for the number you plan around and the per-pound shortcut for quick estimates.

Should I aim for the low end or the high end of my protein range?

It depends on your goal. Maintaining follows activity alone, so the middle of the range is a reasonable starting aim. Losing weight aims at the top of the range, because higher protein helps protect muscle in a calorie deficit. Gaining muscle uses a raised range of 1.8 to 2.4 grams per kilogram, so both ends move up. The floor of about 0.8 grams per kilogram is a deficiency minimum, not an aim point.

How do I check the calculator’s protein target by hand?

Divide pounds by 2.205 to get kilograms, multiply kilograms by the grams-per-kilogram range for your activity level, and divide the daily total by the number of meals. A 70 kg active person at 1.6 to 2.2 grams per kilogram should land at 112 to 154 grams a day. A result roughly double that means pounds were entered as kilograms; a result far below it usually means the wrong activity level was picked.

Does my protein target change if I lose or gain weight?

Yes. The target is weight in kilograms times a range, so a lighter body gives a smaller total at the same range and activity level, and a heavier body gives a larger one. Re-enter your current weight whenever it has changed materially, and re-pick your activity level and goal at the same time, so the target always describes the body and week you have now rather than the ones you had.

What is the difference between the protein range and the 0.8 g/kg floor?

The floor of about 0.8 grams per kilogram per day is the minimum to avoid deficiency in a sedentary adult. The ranges the calculator uses sit well above it: 1.2 to 1.6 grams per kilogram for sedentary adults, rising to 2.0 to 2.4 for athletes, with a gain range of 1.8 to 2.4. At 70 kg the floor is 56 grams a day, while an active person at the same weight aims at 112 to 154 grams. The floor keeps you out of deficiency; the range is built for training, dieting, and building muscle.

Ranges in this guide are the Protein Calculator’s own ranges, stated in grams per kilogram of body weight per day. General information for healthy adults only; not medical advice.