How to use the fill calculator calculator
- 1
Measure the area to be filled
Add a section for each distinct area. A low spot in a lawn and a trench being backfilled are separate problems with separate depths, so keep them apart.
- 2
Work out the depth honestly
The depth is how far the ground has to come up, which is rarely uniform. Measure at several points across the area, and where the depth varies a lot, split it into sections rather than averaging by eye.
- 3
Add a compaction allowance
Fill delivered loose settles when it is placed and compacted, so the finished volume you measured needs more loose material than that. How much depends on the material and the method, so the figure is yours.
- 4
Add a density if buying by weight
Fill is often sold by the ton. Enter a density from your supplier, since YardCalc publishes none: fill materials vary widely and moisture changes the weight considerably.
- 5
Add your pricing
Enter your quoted price per cubic yard or per ton, plus delivery, for an estimated total.
Formula
Fill cubic yards = (square feet x depth in inches) / 324
Equivalent to area times depth in feet, divided by 27. The result is the finished volume; multiply by a compaction allowance of your own for the loose volume to order.
Worked example
A low area 25 feet by 20 feet that needs raising by 4 inches
- 1Find the area: 25 x 20 = 500 square feet.
- 2Convert the depth: 4 in / 12 = 0.3333 ft.
- 3Find the volume: 500 x 0.3333 = 166.67 cubic feet.
- 4Convert to cubic yards: 166.67 / 27 = 6.17 cubic yards.
The area needs about 6.17 cubic yards of finished fill, before any compaction allowance.
Worked examples
Ordering for compaction
The same 6.17 cubic yards with a 20 percent compaction allowance
- 1Finished volume: 6.17 cubic yards.
- 2With a 20 percent allowance: 6.17 x 1.20 = 7.41 cubic yards.
- 3Order the larger figure, since the delivered material is loose.
The 20 percent is a figure chosen for this example, not a published rate. Fill genuinely settles, but how much depends on the material and whether it is compacted in lifts or simply dumped and graded.
A hollow with varying depth
A 500 square foot dip that is 6 inches deep in the middle and tapers to nothing at the edges
- 1The deepest point is 6 inches, but the whole area is not that deep.
- 2For a dish that tapers evenly to the edges, the average depth is roughly half the maximum: about 3 inches.
- 3Volume: 500 x 3 / 324 = 4.63 cubic yards.
- 4Using the 6 inch maximum instead: 9.26 cubic yards, double the requirement.
Using the deepest measurement across the whole area would double this order. Measuring at several points and using a realistic average matters more on fill than on almost any other material.
Why fill depth is the hardest part to measure
For most materials the depth is a specification: a slab thickness, a base depth, a layer depth. For fill it is a measurement of the gap between where the ground is and where you want it, and that gap almost never has one value.
A dip in a lawn is deepest in the middle and zero at its edges. A slope being levelled is deep at one end and nothing at the other. A trench being backfilled has a consistent depth but only over its own footprint.
That makes the average depth the number that matters, and eyeballing it tends to go wrong in a predictable direction: people measure the deepest point, apply it everywhere, and over-order substantially. The worked example above shows that doubling an order. Measure in several places, and use sections where the variation is large.
Finished volume, loose volume, and settlement
The geometry gives you the finished volume: the space that has to end up filled. That is not the volume you order, because fill arrives loose and consolidates once placed.
How much it consolidates depends on the material and the method. Material placed in thin lifts and compacted mechanically settles far less afterwards than material tipped in and graded over, but it takes more loose volume to reach the same finished level. Either way the loose volume exceeds the finished volume.
The reason YardCalc publishes no compaction figure is that the range is wide and the consequences of guessing run both ways. Order too little and the grade comes up short; order too much and you are paying to dispose of the surplus. Ask the supplier or the contractor placing it.
Fill is not one material
The word covers everything from screened topsoil to clay to crushed aggregate, and they behave differently in every way that matters: how they compact, how they drain, how much they weigh, and whether they are suitable under a structure at all.
That is why this page asks for a density rather than offering one. A cubic yard of dry sandy fill and a cubic yard of wet clay are not close in weight, and a supplier selling by the ton needs the right figure to reconcile with.
Which material is appropriate is a separate question again, and one this calculator does not answer. Fill under a slab, a footing, or a retaining wall is usually specified, and using the wrong material there causes problems that no quantity calculation prevents. Take the specification from your plan.
Common mistakes
Where fill estimates go wrong:
- Measuring the deepest point and applying it across the whole area.
- Ordering the finished volume with no allowance for compaction and settlement.
- Averaging across sections of very different depth instead of splitting them.
- Assuming a density to convert to tons rather than asking the supplier.
- Treating all fill as one material when the specification calls for a particular one.
- Forgetting that a backfilled trench already contains a pipe and bedding, which reduces the fill needed.
- Filling against a structure or under a slab without checking what the plan specifies.
Sources and methodology
Every figure on this page comes from geometry, not from a product or materials database. Areas use the standard area formulas, volumes are area multiplied by depth, cylinders use pi times the radius squared times the height, and unit conversions use exact factors: 12 inches to a foot, 27 cubic feet to a cubic yard, and 9 square feet to a square yard.
YardCalc publishes no material density, coverage rate, product dimension, soil swell factor, compaction factor, or price. Those vary by product, by supplier, by soil, and by region, and a figure that is right in one case is wrong in another, so the calculator asks you for the values that apply to your job. Weight estimates appear only when you supply a density.
Nothing here is engineering, safety, or code guidance. Results are planning estimates. Read how every value on the site is derived and checked in the YardCalc calculation methodology.
Fill cubic yards by area and depth
Finished volume for a given area at a given depth, before any compaction allowance. Depth columns are reference values only.
| Area | 2 in | 3 in | 4 in | 6 in | 8 in | 12 in |
|---|---|---|---|---|---|---|
| 50 sq ft | 0.309 | 0.463 | 0.617 | 0.926 | 1.23 | 1.85 |
| 100 sq ft | 0.617 | 0.926 | 1.23 | 1.85 | 2.47 | 3.7 |
| 200 sq ft | 1.23 | 1.85 | 2.47 | 3.7 | 4.94 | 7.41 |
| 300 sq ft | 1.85 | 2.78 | 3.7 | 5.56 | 7.41 | 11.11 |
| 500 sq ft | 3.09 | 4.63 | 6.17 | 9.26 | 12.35 | 18.52 |
| 750 sq ft | 4.63 | 6.94 | 9.26 | 13.89 | 18.52 | 27.78 |
| 1,000 sq ft | 6.17 | 9.26 | 12.35 | 18.52 | 24.69 | 37.04 |
Area one load of fill covers by depth
Square feet that a given volume covers at a given depth, useful for checking whether a delivery will reach across an area.
| Cubic yards | 2 in | 3 in | 4 in | 6 in | 8 in | 12 in |
|---|---|---|---|---|---|---|
| 1 | 162 sq ft | 108 sq ft | 81 sq ft | 54 sq ft | 40.5 sq ft | 27 sq ft |
| 2 | 324 sq ft | 216 sq ft | 162 sq ft | 108 sq ft | 81 sq ft | 54 sq ft |
| 3 | 486 sq ft | 324 sq ft | 243 sq ft | 162 sq ft | 121.5 sq ft | 81 sq ft |
| 5 | 810 sq ft | 540 sq ft | 405 sq ft | 270 sq ft | 202.5 sq ft | 135 sq ft |
| 10 | 1,620 sq ft | 1,080 sq ft | 810 sq ft | 540 sq ft | 405 sq ft | 270 sq ft |
Frequently asked questions
- How much fill do I need?
- Multiply the area by the average depth being filled. A 500 square foot area raised by 4 inches needs 166.67 cubic feet, which is 6.17 cubic yards of finished fill, before any compaction allowance.
- How many cubic yards of fill for a 20 x 20 area?
- A 20 by 20 foot area is 400 square feet. At 3 inches that is 3.70 cubic yards, at 6 inches 7.41 cubic yards, and at 12 inches 14.81 cubic yards.
- Should I order extra for compaction?
- Yes. Fill arrives loose and consolidates as it is placed, so it takes more loose volume than the finished volume you measured. How much more depends on the material and whether it is compacted in lifts, so the allowance is yours to set.
- How do I measure depth in an uneven hollow?
- Measure at several points and use a realistic average, not the deepest point. For a dish that tapers evenly to its edges, the average is roughly half the maximum. Using the maximum everywhere can double the order.
- How many tons is a cubic yard of fill?
- That depends entirely on the material and its moisture, so YardCalc publishes no figure. Dry sandy fill and wet clay differ substantially. Ask your supplier for the density they use and enter it above.
- Can I use any fill under a slab or footing?
- No, and this calculator does not address that. Fill under a structure is normally specified, and the wrong material causes settlement problems. Take the specification from your plan or a qualified professional.
Fill volume is your measured area multiplied by the depth you enter, converted at exactly 27 cubic feet per cubic yard, and reported as finished volume. No compaction factor, material density, or price is assumed, and no fill material is recommended for any application. Quantities come from exact geometry using the dimensions you enter. Confirm product dimensions, installation requirements, local codes, site conditions, safety requirements, and final order quantities with the appropriate manufacturer, supplier, contractor, or professional.
Results are planning estimates. Last reviewed 2026-07-28.