Fill Dirt Calculator

Fill dirt is sold by the cubic yard, and one cubic yard is 27 cubic feet. Once fill is spread and packed, it holds less material than the pile it came from, so the figure you order is larger than the finished volume.

How to use this calculator

1. Measure the area in feet: the length and width of the low spot, or the outline of the grade you are raising.
2. Choose the shape. Use a rectangle for a patch with square edges, a circle for a round hollow and a triangle for a corner cut at an angle. Split an irregular outline into rectangles and run each one.
3. Measure the depth from the current ground to the finished level. Ground is rarely flat, so take readings at several points and enter the average.
4. Check the Extra for waste field. It holds the compaction allowance and starts at the default for this page, so change it only when you have a sourced figure for the soil you are buying.
5. Read the cubic yards figure, then the exact figure beneath it. The difference is the allowance for settling. Multiply the total by the price per cubic yard to estimate the material cost, and round up to a full load if the supplier bills that way.

Worked examples

Cubic yards of fill for common areas, before the compaction allowance

Cubic yards, exact volume without extra for waste.

Why compacted fill needs extra

Loose fill packs down once it is spread and tamped or rolled, so the finished layer holds less material than the pile it came from. The calculator adds 15 percent to the exact volume by default. That default sits inside the published shrinkage ranges, but it is a starting point and not a figure that holds for every soil.

Published shrinkage is 10 to 18 percent for compacted clay, 11 to 35 percent for compacted sand and 5 to 22 percent for rocky or gravelly soil. If the fill will carry weight, such as under a driveway, a shed or a concrete slab, ask an engineer or the supplier which figure fits, and check local compaction rules.

Fill dirt or topsoil?

Fill dirt is subsoil, used to raise a grade, fill a hollow or backfill a trench, and it is meant to be packed and covered. Topsoil holds the organic matter that plants grow in, so it belongs on the surface where roots can reach it.

Using topsoil as fill puts the planting layer underneath, where roots cannot reach it. Put fill dirt below and finish the top with a layer of topsoil if the surface will be planted.

Ordering by the cubic yard

Suppliers quote fill by the cubic yard, so round the total up, then ask how delivery is billed: by the load, by the yard or with a minimum. Ask whether the yards quoted are loose or compacted, because the allowance on this page assumes loose yards.

Mistakes to avoid

• Ordering only the exact volume. The finished low spot will come out short once the fill packs down.
• Filling a hollow where water collects without checking how the water drains away first.
• Filling against a foundation, a retaining wall or a slope without checking local rules. Those projects have their own requirements that this calculator does not cover.

How the calculation works

Convert the depth to feet, then multiply length, width and depth to get cubic feet. Divide that total by 27 to reach cubic yards. A circle uses π × radius² for its area, and a triangle is half of the rectangle with the same base and height.

The allowance is added as a percentage of the exact volume, so the headline figure is the exact volume plus 15 percent of itself. On sloped ground, enter the average depth rather than the deepest point.

How do I calculate fill dirt for a sloped area?

For ground that slopes evenly, measure the depth at the shallow end and at the deep end, add the two readings and divide by two. Enter that average as the depth. If the ground has bumps or dips, take readings at several points, or split the area into smaller sections and run each one.

How far does one cubic yard of fill dirt go at different depths?

One cubic yard is 27 cubic feet, so it covers that many square feet one foot deep. Divide by your depth in feet to see how far a yard goes: the deeper the layer, the less ground it covers. Plan for about 15 percent extra if you will compact the fill.

Common questions