Cubic Yard Calculator for Concrete, Gravel and Soil

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Cubic Yard Calculator

Turn length, width and depth into cubic yards for concrete, gravel, mulch, topsoil or fill. Add as many sections as you like, each with its own depth, and see how far a yard goes at the depth you have chosen.

Any number of sectionsDepth per sectionFour shapesCubic feet and metresCoverage per yardTruck loads
Sections to add up
What one cubic yard covers at each depth
The working
A three foot cube divided into a grid, labelled 3 by 3 by 3 equals 27 cubic feet. Beside it four squares drawn to scale show the footprint that one cubic yard covers at different depths: 324 square feet at one inch, 162 at two inches, 81 at four inches and 54 at six inches.
The four squares are drawn to scale against each other. Look at how much ground the one inch square covers compared with the six inch one, and you can see why a small change in depth costs so much more material than people expect.

How to use this tool

Each section is one area with its own depth, which is the part most calculators get wrong by forcing a single depth on the whole job. A driveway at 4 inches and a garden bed at 3 inches are different sections, and the tool adds them properly. Give each one a name so the working underneath reads like your own job rather than a list of numbers.

Depth goes in inches, not feet, because that is how everyone actually thinks about a layer of material. If your area is an awkward shape, work the square footage out separately and choose the shape option called area I already know. The strip below the results shows what a single cubic yard covers at each common depth, with your current depth highlighted, and that strip is worth more than the total on a lot of jobs.

What a cubic yard actually is

A cubic yard is a cube three feet on every side. Three times three times three is 27, so one cubic yard is 27 cubic feet. That 27 is the only number you need to remember, because everything else on this page falls out of it.

Here is the useful consequence. Spread those 27 cubic feet one inch thick and they cover 324 square feet, because one inch is a twelfth of a foot and 27 times 12 is 324. So the coverage of one cubic yard, in square feet, is simply 324 divided by the depth in inches. At 2 inches that is 162 square feet, at 4 inches it is 81, at 6 inches it is 54. Learn 324 and you can do the rest in your head at the merchant counter.

The relationship is inverse, which is why depth punishes you. Doubling the depth halves the coverage and therefore doubles the material. Going from 3 inches to 4 inches on a driveway sounds like a small change and is a third more stone. Going from 2 inches to 3 inches of mulch on a large bed is fifty percent more, and mulch is sold by the yard.

Yards, bags and the point where one beats the other

Loose material is sold two ways and the crossover is worth knowing. Bags are commonly 2 cubic feet for mulch and soil, sometimes 1.5, so a cubic yard is between 13 and 18 bags. Buy a yard in bags and you will pay two to three times the bulk price for the same material, plus you have to open, tip and dispose of the bags.

Bulk wins on price and loses on logistics. Most yards charge a delivery fee and many have a minimum load, so below about a yard the delivery cost swamps the saving and bags are genuinely cheaper. Above two yards bulk is almost always right. In between, it depends on whether you can collect it yourself, and on whether you have somewhere to tip it that is not the middle of your driveway.

On collection: a full size pickup bed holds roughly 2 cubic yards of loose material by volume, but weight is what stops you, not volume. Two yards of dry mulch is around half a ton and fine. Two yards of wet topsoil is closer to three tons and will flatten the suspension of anything short of a proper truck. Check the payload rating on the door pillar before you fill a bed with soil or stone.

A worked check you can repeat on paper

The tool loads with two sections. The driveway is 30 ft by 10 ft at 4 inches deep. The area is 300 sq ft. Four inches is a third of a foot, so 300 times 0.3333 is 100 cubic feet, and 100 divided by 27 is 3.7037 cubic yards.

Check that against the coverage strip rather than trusting the multiplication. At 4 inches one yard covers 81 square feet. The driveway is 300 square feet, so 300 divided by 81 is 3.7037 yards. The two routes agree, and they are genuinely independent: one goes through cubic feet, the other through the coverage figure.

The garden bed is 12 ft by 4 ft at 3 inches, so 48 square feet at 0.25 ft, which is 12 cubic feet or 0.4444 cubic yards. Add the two sections: 100 plus 12 is 112 cubic feet, which is 4.1481 cubic yards, or 3.1715 cubic metres. You would order 5 yards, or 4 and take the risk, and the tool says so under the total.

Mistakes that catch people out

  • Dividing by 9 instead of 27. Nine is the number for square yards. Cubic yards need 27, because the yard is cubed in all three directions rather than two. This turns a 4 yard order into a 12 yard delivery sitting on your drive.
  • Leaving the depth in inches in the multiplication. Area in square feet times depth in inches gives a number twelve times too big and in no useful unit. Convert the depth to feet first, which is what the working line on this page shows you doing.
  • Using one depth for the whole job. Paths, beds and driveways rarely share a depth. Use a section for each rather than averaging, because the average of two depths weighted by the wrong areas is not the answer.
  • Ordering the exact figure. Material settles, spreads unevenly and gets lost in the edges. Round up to the next half or whole yard, and remember most suppliers will not sell you 3.7 of anything.
  • Confusing a cubic yard with a ton. They are volume and weight and the ratio between them depends entirely on the material. A yard of mulch is around a quarter of a ton, a yard of wet sand is well over a ton. If a supplier quotes by weight you need the density as well as the volume.
  • Filling a pickup by volume. Two yards fits in the bed. Two yards of stone weighs about three tons and most half ton pickups are rated for a fraction of that. The bed running out is not the limit that matters.

How this was checked

The engine was written twice and the versions compared on the same inputs. The definitional cases anchor it: 27 cubic feet returns exactly 1 cubic yard, and one cubic foot returns 0.028316846592 cubic metres, which is the exact figure that follows from a foot being exactly 0.3048 metres. The coverage relation was checked at every depth on the strip, so one yard returns 324 square feet at 1 inch, 162 at 2, 81 at 4, 54 at 6 and 27 at 12 inches. Most usefully, the two independent routes to the driveway answer, area times depth divided by 27 and area divided by the coverage figure, both return 3.7037 cubic yards.

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