Cubic Yard Calculator – How Many Yards of Mulch, Concrete or Soil?
Measure your bed, slab or pile area, choose how deep the material goes, and get the volume in cubic yards — plus the bag count for mulch or concrete, the tonnage for gravel, and a waste allowance so you do not run short on the last wheelbarrow load.
Your project
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How much you need
🧺 Mulch and soil bags
14 bags of 2 cu ft — with 10% waste you need 27.5 ft³ (1.02 yd³), and bags round up to whole bags.
| Breakdown | Value |
|---|---|
| Area | 100 ft² |
| Depth | 0.25 ft (3 in) |
| Volume | 25 ft³ |
| Volume | 0.93 yd³ |
| Volume | 43,200 in³ · 0.71 m³ |
| With 10% waste | 27.5 ft³ · 1.02 yd³ |
A cubic yard is a cube 3 ft by 3 ft by 3 ft — 27 cubic feet. Bags and tons are worked out from the waste-adjusted volume; the headline number is always the true measured volume of your project.
- Volume is area times depth divided by 27: rectangles, circles and triangles all end at the same place, and only the area step differs.
- Depth is the number people guess worst — an extra inch on a big bed is a lot of material, and the calculator defaults to 3 inches for mulch.
- A waste allowance and the bags-versus-bulk decision prevent the two expensive failures: a short order and a second delivery fee.
- One cubic yard, pictured
- Measure in feet, buy in bags or tons
- How deep? A quick guide
- How it works
- The math behind the default example
- Two things that decide whether you buy the right amount
- Depth changes everything: one bed, four depths
- Three shapes, one formula family
- Concrete, gravel, and the weight question
- Ordering checklist: measure twice, order once
- Bags, bulk, and the driveway question
One cubic yard, pictured
A cubic yard is a cube three feet on every side. The cube below fills to the level of your project — and the steps under it show exactly how your number was built, redrawing live as you change the inputs.
Measure in feet, buy in bags or tons
The tools homeowners pair with this one — the same volume in cubic feet, or a deep dive on one material.
How deep? A quick guide
Depth is the number people guess worst — an extra inch on a big bed is a lot of material. These are the standard depths for common jobs; the calculator defaults to 3 in for mulch.
| Project | Suggested depth | Why that depth |
|---|---|---|
| Mulch in flower beds | 3 in | Blocks weeds and holds moisture without smothering roots |
| Compost top-dressing on a lawn | 1 in | Feeds the soil without burying the grass |
| Sand base under pavers | 1 in | A screeded bedding layer over compacted gravel |
| Pea gravel patio or path | 2 in | Deep enough to cover, shallow enough to walk on |
| Concrete slab (patio, shed base) | 4 in | The standard residential slab thickness |
| Gravel driveway | 4 in | Often laid as two compacted 2 in layers |
| Topsoil for a new lawn | 6 in | Gives grass roots a full bed of good soil |
Worked check: a 10 × 10 ft bed at the 3 in mulch depth is exactly this page’s default example — 25 ft³, or 0.93 yd³.
How it works
Area first, then depth, then the shopping list.
Work out the area
Pick the shape that matches your project — rectangle, circle or triangle — and enter its size in feet, inches, yards or metric. The area is found in square feet: length × width, π × radius², or half base × height.
Multiply by the depth
Area × depth gives the volume in cubic feet. Divide by 27 — the cubic feet in one cubic yard — and you have the number suppliers quote and price by.
Add waste, then convert to bags or tons
Real projects settle, spill and sit on uneven ground, so a waste allowance is added before the shopping maths: bags are the adjusted volume divided by the bag size, rounded up; gravel is adjusted yards × 1.4 tons.
The math behind the default example
Step 1 — the area. A rectangular bed 10 ft long and 10 ft wide: 10 × 10 = 100 ft².
Step 2 — the depth in feet. Mulch goes down 3 in deep, and 3 ÷ 12 = 0.25 ft. Depths are almost always given in inches, so this conversion is where most hand calculations go wrong.
Step 3 — the volume. 100 × 0.25 = 25 ft³. In cubic yards: 25 ÷ 27 = 0.9259, shown as 0.93 yd³ — the headline figure, with no waste added.
Step 4 — what to actually buy. With the default 10% waste allowance, 25 × 1.10 = 27.5 ft³ (1.02 yd³). In 2 cu ft bags: 27.5 ÷ 2 = 13.75, and since bags only come whole, that rounds up to 14 bags. Skip the waste and it would be 13 — one bag short if anything settles or spills.
Two things that decide whether you buy the right amount
Why the waste percentage exists, and the point where a bulk delivery beats bags.
The volume you calculate is the volume of a perfect box. Real material does not behave like one. Loose mulch and soil compact down once they are watered and walked on — a bed that measures exactly 3 in deep on Saturday can sit nearer 2½ in a month later. Gravel sinks into soft soil at the edges, concrete spills and sticks to the mixer, and almost no garden bed is perfectly level: the low corner quietly takes a third more than the high one.
That is why suppliers and landscapers add a waste allowance before ordering: about 10% for mulch, soil and gravel, about 5% for concrete (which is placed, not spread, so less of it wanders off). The calculator keeps the two numbers separate on purpose — the headline is your project’s true measured volume, and the waste-adjusted figure is what the bag and ton counts are built from, so you can see exactly how much of your order is insurance.
One cubic yard is 27 cubic feet. In 2 cu ft bags that is 13.5 bags — in practice 14 — and in 3 cu ft bags it is 9. Bagged material is convenient, stays tidy, and can be carried through a side gate one bag at a time; it is also usually the most expensive way to buy a yard of anything, because you are paying for the bag, the pallet and the handling.
The usual rule of thumb: under half a yard, bags are simpler. Around a yard, compare the bag total (the calculator will work it out if you add a price per bag) against a bulk delivery quote plus its delivery fee. Beyond two yards, bulk almost always wins on price and on trips — one dump on the driveway instead of thirty bags in the car. Either way, order against the waste-adjusted figure: a second delivery fee costs more than a little leftover mulch.
Depth changes everything: one bed, four depths
The same 10 by 10 foot bed needs wildly different orders depending on depth, and depth is the figure most often guessed. The table below holds the area fixed at 100 square feet and varies only the depth, using the page’s own formulas: volume in cubic feet is area times depth in feet, cubic yards is cubic feet divided by 27, and bag counts use the 10 percent waste allowance with 2 cubic foot bags, rounded up.
At 2 inches deep, the bed needs 16.67 cubic feet, or 0.62 cubic yards, and 10 bags with waste. At the standard 3 inches it needs 25 cubic feet, 0.93 cubic yards, and 14 bags. At 4 inches it needs 33.33 cubic feet, 1.23 cubic yards, and 19 bags. At 6 inches it needs 50 cubic feet, 1.85 cubic yards, and 28 bags. Doubling the depth from 3 inches to 6 inches doubles the order, from 14 bags to 28, which is obvious once stated and still the commonest ordering surprise, because a bed that looks only slightly deeper can easily be twice as deep in the low corner where material collects.
| Depth | Volume | Cubic yards | With 10% waste | 2 cu ft bags |
|---|---|---|---|---|
| 2 in | 16.67 ft³ | 0.62 yd³ | 18.33 ft³ | 10 |
| 3 in | 25.00 ft³ | 0.93 yd³ | 27.50 ft³ | 14 |
| 4 in | 33.33 ft³ | 1.23 yd³ | 36.67 ft³ | 19 |
| 6 in | 50.00 ft³ | 1.85 yd³ | 55.00 ft³ | 28 |
The practical rule follows directly. Measure the depth in several places, not one, and use the average, because a bed that measures 3 inches at the edge and 5 inches in the middle is not a 3-inch bed. If the measurements vary by more than an inch, the bed is not level, and the low spots will take the extra material whether it was ordered or not. Ordering against the average depth, with the waste allowance on top, is cheaper than ordering against the shallowest measurement and paying a second delivery fee for the shortfall.
Three shapes, one formula family
Rectangles, circles and triangles all end at the same place: area in square feet, times depth in feet, divided by 27. Only the area step differs.
The rectangle is length times width. A 10 by 10 foot bed is 100 square feet, and at 3 inches deep it needs 25 cubic feet, or 0.93 cubic yards, the default example on this page. The circle is pi times radius squared, and the radius is half the diameter, which is the step most often skipped: a round bed 10 feet across has a radius of 5 feet, an area of about 78.54 square feet, and at 3 inches deep it needs 19.63 cubic feet, or 0.73 cubic yards. Using the diameter as the radius would quadruple the area, and would order nearly four times too much material, so the halving step is worth doing deliberately rather than from memory.
The triangle is half the base times the height, where the height is the perpendicular distance from the base to the opposite corner, not the length of the sloping side. A triangular bed with a 10-foot base and an 8-foot height is 40 square feet, and at 3 inches deep it needs 10 cubic feet, or 0.37 cubic yards. A bed that is not a neat triangle should be split into a rectangle plus a triangle, or into two triangles, and the volumes added: two small honest shapes beat one large approximate one, because the error in a single rough shape is invisible until the delivery arrives. For any shape, the depth conversion is the same and is the step most often forgotten: depth in inches divided by 12 gives depth in feet, and the volume must use feet throughout, never a mixture of inches and feet in the same multiplication.
Metric users can run the same shapes and convert at the end. The default rectangle is 0.71 cubic metres, because 0.93 cubic yards times 0.7646 cubic metres per cubic yard is 0.71. Suppliers who price by the cubic metre will quote against that figure, and the bag counts do not change, because bags are sold by cubic feet regardless of the unit the volume is quoted in. Convert the headline, not the shopping list.
Concrete, gravel, and the weight question
Mulch, concrete and gravel all come by the cubic yard, but they are bought, carried and priced differently, and the differences decide the order.
Concrete is the most unforgiving of the three, because it cannot be returned and a short order stops the pour. A 10 by 10 foot slab at the standard 4 inches thick needs 33.33 cubic feet, or 1.23 cubic yards. An 80-pound bag yields 0.6 cubic feet, so the slab needs 55.6 bags, which is 56 bags before waste, or 59 bags with the 5 percent waste allowance this page recommends for concrete rather than the 10 percent used for mulch. In 60-pound bags at 0.45 cubic feet each it is 75 bags before waste. For anything much bigger than this slab, a ready-mix delivery is usually the saner option, because bagged concrete at this scale means dozens of bags, a mixer, and a pour that must finish before the first batch sets.
Gravel is bought by volume but carried by weight, and the conversion on this page is 1.4 tons per cubic yard for typical gravel and crushed stone, or about 2,800 pounds. A cubic yard of gravel therefore weighs roughly what a small car weighs, which is why delivery vehicles and driveways matter: a bulk delivery of several yards is several tons on the driveway in one place, and a vehicle that cannot reach the spot cannot deliver it. The 1.4-ton figure is for gravel and crushed stone specifically. It should not be applied to soil, mulch or sand, whose weights per yard differ considerably, and this calculator does not state a tons figure for those materials, so none is given here. If a supplier quotes soil by the ton, ask for the volume equivalent as well, and compare volumes, not weights, across materials.
Mulch sits between the two. It is light enough to carry in bags, bulky enough that a large bed needs a bulk delivery, and compressible enough that the waste allowance matters most: a bed that measures exactly 3 inches deep on the day it is spread can sit nearer 2.5 inches a month later, once the mulch has been watered and walked on. That settling is not a defect in the material. It is the reason the 10 percent allowance exists, and topping up a settled bed to its original depth is normal maintenance, not evidence that the first order was short.
Ordering checklist: measure twice, order once
Five checks that cost minutes and prevent the two expensive failures: a short order, and a second delivery fee.
First, measure the area in feet, and measure it twice, once in each direction, because a bed remembered as 10 by 10 that is actually 11 by 10 is 10 percent larger, and the order will be 10 percent short before waste is even considered. Second, measure the depth in at least three places and use the average, and keep mulch a few inches away from trunks and stems whatever depth is chosen. Third, decide the waste allowance deliberately: about 10 percent for mulch, soil and gravel, about 5 percent for concrete, which is placed rather than spread, so less of it wanders off. The calculator keeps the headline volume and the waste-adjusted figure separate on purpose, so the insurance in the order is visible rather than hidden.
Fourth, compare bags against bulk at the crossover, not by habit. Under half a yard, bags are simpler. Around a yard, compare the bag total against a bulk delivery quote plus its delivery fee. Beyond two yards, bulk almost always wins on price and on trips: one dump on the driveway instead of thirty bags in the car. Either way, order against the waste-adjusted figure, because a second delivery fee costs more than a little leftover mulch, and leftover mulch, unlike leftover concrete, keeps for the next bed. Fifth, confirm the unit with the supplier before paying: cubic yards, cubic feet, cubic metres, bags and tons are all in use, and a quote in the wrong unit is the easiest ordering error to make and the hardest to spot after the truck has left.
Bags, bulk, and the driveway question
The arithmetic gives the volume. Delivery decides how it arrives, and the delivery decision deserves the same care as the measurement.
Bagged material is convenient, stays tidy, and can be carried through a side gate one bag at a time, but it is usually the most expensive way to buy a yard of anything, because the price includes the bag, the pallet and the handling. Bulk material arrives in one dump on the driveway, which is cheaper per yard and far fewer trips, but it needs a vehicle that can reach the spot, a driveway that can take the weight, and a place to keep a pile that will sit there until it is spread. Gravel makes the weight question concrete: a cubic yard weighs about 1.4 tons, so a bulk delivery of several yards is several tons in one place, and a soft driveway or a steep access can turn a cheap delivery into a stuck truck.
The crossover rule on this page is the practical guide. Under half a yard, bags are simpler, because the delivery fee alone can exceed the saving on the material. Around a yard, compare the bag total against a bulk delivery quote plus its delivery fee, using the waste-adjusted figure for both, because comparing an unadjusted bag count with an adjusted bulk quote flatters the bags. Beyond two yards, bulk almost always wins on price and on trips. Either way, order against the waste-adjusted figure: a second delivery fee costs more than a little leftover mulch, and leftover mulch, unlike leftover concrete, keeps for the next bed or the next top-up.
Timing matters as much as quantity. Order mulch and soil for the week they will be spread, not the month before, because a pile left through rain compacts, grows weeds, and loses the loose structure that made it spreadable. Order concrete for the day of the pour, with the crew ready, because a short concrete order stops the pour and a delayed pour wastes the batch. And confirm the unit with the supplier before paying, every time: cubic yards, cubic feet, cubic metres, bags and tons are all in use, and a quote in the wrong unit is the easiest ordering error to make and the hardest to spot after the truck has left. The calculator gives the volume in yards, feet and metres together precisely so that check can be made before the order, not after it.
Slopes: the average-depth method, done honestly
A sloped bed has no single depth, so the volume calculation needs an average depth, and the honesty of the order depends on how that average is taken. Measure the depth at several points spread across the bed, including the shallowest and deepest spots, and average the readings. The average depth times the area, divided by 27, is the volume in cubic yards, and the companion guide on figuring cubic yards works the method with a bed that runs from 2 inches to 6 inches deep.
Two cautions apply. First, an average of two readings at the extremes is only reliable if the slope is even; a bed with a hollow or a ridge needs more readings, because one deep pocket can add a large volume that two readings miss. Second, material spread on a slope migrates downhill in rain and underfoot, so the finished depth on the slope will be thinner at the top and thicker at the bottom than the depth ordered. Order against the average, allow the usual waste on top of it, and expect to top up the high end of a steep slope after the first heavy rain.
Weight, trucks, and the driveway question
Volume decides the order; weight decides how it arrives. A cubic yard of concrete weighs about 4,000 pounds, gravel about 2,800, topsoil or dirt about 2,200, and mulch only about 400 to 800, so the same 5-yard order weighs anything from about a ton of mulch to about ten tons of concrete. Trucks carry by weight as well as by volume, and a supplier will split a heavy order across loads or refuse a driveway delivery that the truck cannot reach or the surface cannot bear.
Ask three questions before ordering: what is the truck’s payload limit, can it reach the drop point without crossing soft ground or a septic field, and will the driveway bear a loaded truck without cracking. A standard residential driveway is not built for repeated heavy-axle loads, and the repair costs more than the delivery saving. For large concrete or gravel orders, a street drop with a wheelbarrow shuttle is often the honest answer, and the companion guide on materials sets out the per-yard weights to plan it with.
Cubic yard questions, answered
The conversions, bag counts and depths people ask about most — with the arithmetic shown.
How many cubic feet are in a cubic yard?
27. A cubic yard is a cube measuring 3 ft by 3 ft by 3 ft, and 3 × 3 × 3 = 27. Every conversion on this page runs through that number: cubic feet ÷ 27 = cubic yards, and cubic yards × 27 = cubic feet. It is also why a yard of material in 2 cu ft bags takes 13.5 bags — 27 ÷ 2.
How do I calculate cubic yards for a garden bed?
Measure the bed’s length and width in feet, decide the depth in inches, then: length × width × (depth ÷ 12) ÷ 27. The depth ÷ 12 step converts inches to feet, and it is the step most often forgotten. A 10 × 10 ft bed with mulch 3 in deep is 10 × 10 × 0.25 ÷ 27 = 0.93 yd³. For a round bed, use the circle shape: π × radius² × depth in feet ÷ 27.
How many bags of mulch make a cubic yard?
It depends on the bag size. A cubic yard is 27 ft³, so you need 27 bags of 1 cu ft, 13.5 bags of 2 cu ft (14 in practice, since bags are whole), or 9 bags of 3 cu ft. Add your waste allowance first — at 10% extra, one yard becomes 29.7 ft³, which is 15 bags of 2 cu ft.
How deep should mulch be?
Three inches is the standard depth for flower beds and around shrubs: deep enough to block most weeds and hold moisture, shallow enough not to smother roots or rot stems. Two inches works for a yearly top-up over existing mulch; four inches suits a brand-new bed over bare soil. Keep mulch a few inches away from trunks and stems, whatever depth you choose.
How many bags of concrete do I need for a 10 × 10 slab?
A 10 × 10 ft slab at the standard 4 in thickness needs 33.33 ft³ of concrete (1.23 yd³). An 80 lb bag yields 0.6 ft³, so 33.33 ÷ 0.6 = 55.6 — that is 56 bags, or 59 bags with a 5% waste allowance. In 60 lb bags (0.45 ft³ each) it is 75 bags before waste. For anything much bigger, a ready-mix delivery is usually the saner option.
How much does a cubic yard of gravel weigh?
About 1.4 tons (2,800 lb) for typical gravel and crushed stone, which is the figure this calculator uses. The honest range is roughly 1.2 to 1.6 tons per cubic yard: rounded pea gravel sits at the lighter end, dense crushed stone and damp material at the heavier end. If the exact weight matters — for a trailer limit, say — ask the supplier for their figure for the specific stone.
Should I use 5% or 10% waste for my project?
Use 10% for mulch, soil and gravel, and 5% for concrete, which is the split this calculator recommends. The reason is how the material behaves after it is placed: loose mulch and soil settle, spill and sit on uneven ground, so a bed that measures exactly 3 inches deep on Saturday can sit nearer 2.5 inches a month later, and gravel sinks into soft soil at the edges. Concrete is placed, not spread, so less of it wanders off, and 5% covers spillage and the material that sticks to the mixer. The calculator keeps the headline volume and the waste-adjusted figure separate, so the insurance in the order is visible. If the ground is very uneven or the bed has a steep slope, 10% is the floor, not the ceiling.
How do I convert cubic yards to tons?
Only for gravel and crushed stone, where this calculator uses 1.4 tons per cubic yard, about 2,800 pounds. Multiply the cubic yards by 1.4: two cubic yards of gravel weigh about 2.8 tons. Do not apply that figure to soil, mulch or sand, whose weights per yard differ considerably, and this calculator states no tons figure for those materials. If a supplier quotes soil by the ton, ask for the volume equivalent as well and compare volumes, not weights, across materials. A ton of mulch and a ton of gravel are very different amounts of material, and ordering by weight across materials is how beds end up short.
My supplier prices by the cubic metre. How do I convert?
Multiply cubic yards by 0.7646 to get cubic metres. The default bed on this page is 0.93 cubic yards, which is 0.71 cubic metres, and that is the figure a metric supplier will quote against. Convert the headline volume, not the shopping list: bag counts are sold by cubic feet regardless of the unit the volume is quoted in, so the 14 bags for the default bed stay 14 bags whether the volume is stated as 0.93 cubic yards or 0.71 cubic metres. If the supplier’s quote comes back in cubic metres, divide by 0.7646 to check it against this calculator’s cubic yards before paying.
What if my bed is an irregular shape or sloped?
Split it into honest shapes and add the volumes. A bed that is mostly rectangular with a triangular corner is a rectangle plus a triangle, and each part uses its own area formula with the same depth step. For a sloped bed, measure the depth in several places and use the average, because the low spots take more material than the high spots save, and a single measurement at the shallow edge will under-order. If the depth varies by more than an inch across the bed, consider levelling first: no waste allowance fixes a bed whose depth was never really known, and the cheapest material is the material ordered once, against a measured average, rather than twice, against a guess.
How much does a cubic yard of concrete weigh compared with mulch?
A cubic yard of concrete weighs about 4,000 pounds, while a cubic yard of mulch weighs only about 400 to 800 pounds, depending on the material and how wet it is. Gravel sits between them at about 2,800 pounds and dirt at about 2,200. The same volume can therefore weigh ten times as much, which is why trucks are limited by weight as well as by volume.
Can a delivery truck drive onto my driveway?
Sometimes, and the supplier decides, not the customer. A loaded truck can weigh many tons, and a residential driveway, soft ground or a septic field may not bear it. Ask the supplier about the truck’s weight and reach before ordering, and expect a street drop with a wheelbarrow shuttle for heavy orders or fragile surfaces. The cost of repairing a cracked driveway exceeds any delivery saving.
How do I measure a circular bed in cubic yards?
Measure the diameter, halve it for the radius, and use pi times the radius squared times the depth, all in feet, then divide by 27. A bed 10 feet across and 4 inches deep needs about 0.87 cubic yards before waste, so order 1 yard. The companion guide on figuring cubic yards works the circle, rectangle and slope cases side by side with the arithmetic shown.
Should I order dirt and concrete the same way?
No. Concrete is ordered by volume and placed before it sets, so the order must be exact and timed to the pour, with little room for a second trip. Dirt, gravel and mulch are forgiving: an extra yard can be spread, stored or used elsewhere, and a shortfall is a second delivery rather than a failed pour. Order concrete tight and dirt generous, and keep the two methods apart in the plan.
More measuring and materials tools
Area, volume and the single-material calculators that sit next to this one.
Cubic Feet Calculator
Volume in cubic feet for any box or space.
🍂Mulch Calculator
How much mulch your beds need, by depth.
🧱Concrete Calculator
Yards and bags for slabs and footings.
🪨Gravel Calculator
Gravel volume and weight for drives and paths.
📐Area Calculator
Square footage for rectangles, circles and more.
📦How to Figure Cubic Yards
Circles, rectangles and slopes.
🏗️How Many Cubic Yards Do I Need?
Concrete, dirt and mulch, by project.