How to use the dirt calculator
Enter the size of the area and how deep you need to fill it. The calculator works out the volume of the hole or the raise, then adds a compaction allowance, because dirt delivered loose in a truck shrinks when it's compacted. The result is what to order. It also gives the weight and the number of truckloads for the truck size your supplier uses.
The formula
compacted volume = area × depth
loose volume to order = compacted volume × (1 + compaction allowance)
tons = loose cubic yards × density
Worked example: raising a 30 × 20 ft area by 6 inches
- Compacted volume: 600 ft² × 0.5 ft = 300 ft³ = 11.1 yd³.
- Add 25% for compaction: 375 ft³ = 13.9 yd³ loose.
- Weight at 1.1 tons per yard: about 15.3 tons.
- With a tandem truck carrying about 12 yards: 2 loads.
Filling and grading tips
- Compact in lifts. Spread 4 to 6 in at a time and compact each layer with a plate compactor or roller. Dumping 2 ft and compacting the top just compacts the top.
- Slope away from the house. A common rule is at least 6 in of fall in the first 10 ft away from the foundation. Check your local code.
- Clean fill only. Ask for fill without large rocks, roots, construction debris or organic matter, which rots and settles.
- Finish with topsoil where grass will grow; fill dirt is poor for plants. The topsoil calculator handles that layer.
- Call 811 before digging or regrading near buried utilities.
Common mistakes
- Ordering the exact volume. Without the compaction allowance you'll come up a quarter short.
- Guessing the depth. Run a string line and measure at several points. Low spots are often deeper than they look.
- Overloading a pickup. A single cubic yard of dirt weighs over a ton.
Questions people ask
How much fill dirt do I need?
Multiply the area by the depth you need to fill, in feet, and divide by 27 for cubic yards. Then add 20 to 30% if you'll compact it, because loose dirt from a truck shrinks when it's compacted. Raising 600 square feet by 6 inches needs 11.1 yards compacted, about 13.9 yards loose.
How much does a yard of fill dirt weigh?
Loose fill dirt is roughly 1 to 1.15 tons per cubic yard when dry, and up to about 1.35 tons wet. This calculator uses 1.1 tons. Clay and wet soil are heavier.
How many yards of dirt are in a dump truck?
Roughly 5 to 8 cubic yards for a single-axle truck, 10 to 14 for a tandem and 14 to 16 for a tri-axle, but weight limits often cap heavy, wet dirt below the bed's volume. Ask your supplier how much they load.
What's the difference between fill dirt and topsoil?
Fill dirt is subsoil: low in organic matter, it compacts firmly and is used to raise grades, fill holes and backfill. Topsoil is the dark, organic top layer for growing grass and plants. Use fill underneath and finish with 4 to 6 inches of topsoil where you want a lawn.
How much does fill dirt compact?
Loose dirt delivered by truck typically loses 20 to 30% of its volume when properly compacted in layers. Compacting in 4 to 6 inch lifts with a plate compactor gives a firm result that won't settle later.
Sources and assumptions
- Loose fill density about 1.0-1.15 tons/yd³ dry and loose-to-compacted shrinkage of 20-30% are standard earthwork estimating figures (e.g. Caterpillar Performance Handbook material tables). Your soil may differ.
- Truck capacities vary by state weight limits and the material. Ask your hauler.
Last reviewed 27 October 2026. Every formula on this page is checked against the worked example above in our automated tests. Found a problem? Tell us.