Acres to Cubic Yards Calculator

How big an acre is

An acre is exactly 43,560 square feet, which works out to 4,840 square yards. If you laid that area out as a perfect square, each side would be about 208.7 feet long.

Most acres aren’t square, though. A long strip along a fence line, an L-shaped lot or an irregular pasture can each be one acre, as long as the area adds up to 43,560 square feet. That’s why it helps to think of an acre as an amount of ground rather than a fixed shape.

A common mix-up is picturing an acre as 100 yards on each side. That square covers 10,000 square yards, or about 2.07 acres, so it’s more than twice the size of a real acre. If you’ve been estimating material with that picture in mind, your order would come out roughly double what you need.

Acreage tells you how much ground you’re covering, but not how much material it takes. You can’t turn acres into cubic yards until you pick a depth, which is why the calculator above asks for one. If you measured your site in feet instead of acres, the square feet to cubic yards calculator lets you skip the acre step.

Cubic yards per acre for spreading

Every inch of depth over one acre takes about 134.44 cubic yards. Because spreading jobs are measured in fractions of an inch, that one number scales to almost any rate: a ¼-inch compost topdressing comes to about 33.6 cubic yards per acre, while a 2-inch layer is closer to 268.9.

Topdressing means spreading a thin layer of material over the surface of turf rather than digging it in. How thick that layer should be depends on the job. The Cornell sports field topdressing guide puts topdressing at ⅛ to ⅜ inch when seeding or overseeding, and recommends no more than ¼ inch of compost per application. Penn State Extension gives similar figures for established turf, around ¼ inch of compost, and a much heavier 1 to 2 inch layer when compost is worked into the soil 4 to 6 inches deep before planting.

Rates this thin are hard to spread evenly by hand across several acres. Most people work out the cubic yards per acre, multiply by their acreage to place the order, and let the spreader setting take care of even coverage. For a single lawn rather than a field, the lawn top-dressing calculator works in square feet, and if you’re spreading soil instead of compost, the topsoil calculator covers that material.

Filling or digging out an acre

An acre raised one foot works out to 1,613.33 cubic yards of dirt. That figure describes the finished, packed ground, though, not the amount you order or haul. Soil takes up a different amount of space depending on its state, so earthwork crews usually talk about three kinds of cubic yards:

• Bank cubic yards: soil still in the ground, undisturbed.
• Loose cubic yards: soil after it’s dug, sitting in a truck or a pile.
• Compacted cubic yards: soil spread and packed down in place.

Moving between these states is what makes an acre of fill or excavation take more truckloads than the plain volume suggests.

Raising or leveling ground with fill

Fill arrives loose and shrinks when you compact it. Based on the FHWA earthwork design guidance, loam takes about 1.5 loose cubic yards for every compacted cubic yard when the soil is damp, and about 1.7 when it’s dry. So if you order exactly 1,613.33 cubic yards to raise an acre by a foot, you’ll likely come up well short once the roller has been over it.

The calculator’s “Fill & compact” option adds a 50% allowance by default, and you can change that percentage if your supplier gives you a figure for their material. For single-site fill jobs measured in feet, the fill dirt calculator handles the same adjustment.

Digging out a site

Excavation works the other way around. Breaking soil out of the ground adds air, so it swells, and the swell depends on the soil type. FHWA lists typical swell from bank to loose as:

• sand: about 11%
• loam: about 43% when damp to 50% when dry
• topsoil: about 56%
• clay: about 50% when dry to 67% when damp

That swollen volume is what fills your trucks and your disposal site. A dig that measures 4,840 cubic yards in the ground becomes roughly 6,921 to 7,260 loose cubic yards of loam, so truck counts and dump space should always be planned on the loose number.

The 10 yd³ truck in these examples is only an assumption to make the math concrete. Enter your hauler’s real capacity in the calculator above, since load counts change quickly with truck size.

Weight follows the same logic. The calculator converts your volume to US tons using a typical loose weight for the material you pick, but soil in the ground is denser than soil in a pile: FHWA puts loam at about 3,030 to 3,370 pounds per cubic yard in place, compared with about 2,070 to 2,360 pounds loose. For materials beyond the six in the calculator, use the cubic yards to tons converter.

Treat all of these factors as starting points rather than exact values. FHWA notes that swell and shrink figures can vary by about a third in either direction, so a soil test or your supplier’s own numbers will always beat a general table.

Acres to cubic yards FAQs