Fill Dirt Calculator
Cubic yards & tons of fill dirt
Filling a low spot or building up a grade? Enter the area and fill depth to get the cubic yards and tons of fill dirt to order.
Fill dirt vs topsoil, and why the difference matters
Calculating fill dirt starts with cubic yards of dirt, and a fill dirt calculator tons figure follows from the density.
Fill dirt is subsoil: cheap, dense, largely free of organic matter. That last property is exactly why it works. Organic matter decomposes, and anything that decomposes under a patio or against a foundation leaves a void behind. Fill dirt is structural material for building grade, not growing medium.
The practical consequence is that you almost always buy both: fill dirt for the bulk, then topsoil capping the top 4 to 6 inches wherever you intend to plant. Buying screened topsoil for the whole depth is a common and expensive mistake — it costs several times more and performs worse structurally.
| Depth | Cubic yards | Tons |
|---|---|---|
| 3 in | 0.97 yd³ | 1.25 |
| 6 in | 1.94 yd³ | 2.49 |
| 12 in | 3.89 yd³ | 4.99 |
| 18 in | 5.83 yd³ | 7.48 |
| 24 in | 7.78 yd³ | 9.98 |
Worked example: levelling a 30 × 20 ft yard
Raising a 600 ft² area by 12 inches:
| Step | Working | Result |
|---|---|---|
| Bare volume | 600 ft² × 1 ft | 600 ft³ = 22.2 yd³ |
| Plus 5% | 23.33 yd³ | |
| As weight | 23.33 × 1.28 | 29.93 tons |
| Truck loads | at 10 to 14 yd³ | 2 loads |
| Plus topsoil cap (4 in) | separate order | about 7.8 yd³ |
One cubic yard of fill dirt weighs about 2,565 lb, or 1.28 tons. That figure matters when ordering, because heavy material hits a truck's weight limit before its volume limit — a truck rated for 14 yards of mulch may only legally carry 8 or 9 of fill dirt.
Compaction, and why you order extra
Loose fill settles. A yard delivered loose occupies noticeably less once it is compacted and rained on, and the settling continues for months if you do not compact it deliberately. That is the whole reason for a waste allowance here, and why 10 to 15% is safer than the 5% default for anything structural.
- Place and compact in 6 inch lifts. One big dump compacts only at the top and settles unevenly for a year.
- Moisture matters. Fill compacts best slightly damp. Bone dry will not bind and saturated will pump under the plate.
- Do not fill over topsoil, sod or organic debris. Strip it first, or it decomposes and leaves a soft layer under your new grade.
- Never fill against a foundation without checking. Fill exerts lateral pressure on a wall that may not be designed for it, and it changes where water goes.
Grading away from the building
Any fill near a house needs to slope away at about 6 inches over the first 10 feet — a 5% grade. This is the single most effective and most frequently neglected piece of foundation protection there is, and it costs almost nothing while the dirt is already loose.
Two things to keep clear of: do not raise the grade above the siding line or the damp-proof course, and do not bury weep holes in brick veneer. Both invite water and pests directly into the wall. If your fill would reach either, the answer is a retaining edge or a swale, not more dirt.
For large regrades near structures, or anywhere the fill will support something later, get the finished grade checked. Drainage mistakes at this stage are cheap to prevent and very expensive to undo.
How this fill dirt calculator works out its numbers
Volume is area × depth at 27 ft³ per cubic yard, with 5% added by default. Use 10 to 15% for structural fill that will be compacted.
- Density is 95 lb/ft³, giving about 1.28 tons per cubic yard. Real fill ranges roughly 90 to 115 lb/ft³ with clay content and moisture; wet fill weighs more without occupying more volume, so yardage is the stabler figure to order by.
- Compaction is not modelled. Loose delivered volume exceeds compacted in-place volume by a margin that depends on the material and the effort, which is why the allowance should rise for structural work.
- Excavation and disposal are not included, and neither is the topsoil cap you will need over any area to be planted.
- Truck capacity of 10 to 14 cubic yards is typical for a tandem dump truck, but weight limits usually bind first with material this dense.
- Grading guidance (6 in over 10 ft away from a building) reflects common US practice. Anything structural or near a foundation should be checked locally.
Reviewed September 2026.
Figures reviewed . Every worked example on this page is checked against the calculator above.
Fill Dirt Calculator: frequently asked questions
How much fill dirt do I need?
Multiply area by depth and divide by 27. A 30 × 20 ft area raised 12 inches needs about 23.33 cubic yards or 29.93 tons including 5% overage, which is two truck loads.
How many tons of fill dirt in a cubic yard?
About 1.28 tons at a typical 95 lb per cubic foot, though it ranges 1.2 to 1.5 depending on moisture, clay content and compaction. Wet fill weighs considerably more without taking up more space.
Is fill dirt the same as topsoil?
No. Fill dirt is dense subsoil with little organic matter, used to build grade. Topsoil is the dark, nutrient-rich upper layer used for growing. Build with fill dirt, then cap the top 4 to 6 inches with topsoil where you will plant.
Should I compact fill dirt?
Yes, in 6 inch lifts. Loose fill keeps settling for months and leaves dips, or voids near a foundation. Compact each lift slightly damp, since bone-dry fill will not bind and saturated fill pumps under the plate.
How much extra fill dirt should I order?
10 to 15% for anything structural, above the 5% default. Fill loses noticeable volume as it is compacted and as moisture leaves it, so the loose yardage delivered is not the finished yardage in place.
Can I put fill dirt over grass?
Strip the sod and any organic debris first. Grass and topsoil buried under fill decompose over the following year and leave a soft, settling layer exactly where you wanted solid ground.
How far should the ground slope away from a house?
About 6 inches over the first 10 feet, a 5% grade. Keep the finished level below the siding line and damp-proof course, and never bury weep holes in brick veneer.
How many truck loads is 20 cubic yards of fill?
Two, since a standard tandem dump truck carries 10 to 14 cubic yards. But fill dirt is heavy enough that trucks often hit their weight limit first, so a truck rated for 14 yards of mulch may only carry 8 or 9 of dirt.