Fill Dirt Calculator
Fill dirt is the material where everyone under-orders, because dirt shrinks. Dump 10 loose yards into a hole, run a compactor over it, and you're standing in a dip: compacted fill takes up about 20 to 25% less space than it did on the truck. This tool asks the question others skip, whether you're compacting, and inflates the order to match. Enter the area and depth and you'll get loose yards to order, tons for the quote, and how many dump truck loads that means.
Dirt shrinks, orders shouldn't
Fill dirt is the only material on this site you deliberately over-order, and not for waste: for physics. Excavated soil arrives fluffed with air. Run a compactor over it and it loses 20 to 25% of its volume, which is why the hole you "filled" on Saturday is a dip by the next rain. The compaction toggle above adds the allowance automatically, so the grade you plan is the grade you end up standing on.
Loose vs compacted, at a glance
| Finished need (compacted) | Order loose | Weight | Tandem loads |
|---|---|---|---|
| 5 yd | 6.3 yd | ~7 tons | 1 |
| 10 yd | 12.5 yd | ~14 tons | 1-2 |
| 20 yd | 25 yd | ~28 tons | 2-3 |
| 40 yd | 50 yd | ~55 tons | 4-5 |
Weights figure at 1.1 tons per loose yard for typical dry fill. Wet clay runs 1.3 or higher, which matters if the quote is by the ton instead of the yard.
Fill dirt vs topsoil vs select fill
Fill dirt is subsoil: clay, sand, rock mix with no organic matter, which is exactly why it holds grade, because nothing in it decomposes and re-settles. Topsoil is the opposite: living, organic, spongy, for the top 4 to 6 inches where things grow, and never structural. Between them sits select fill, screened and spec'd material (often a sandy clay) that engineers call out under slabs and foundations. Filling a low yard: cheap fill below, topsoil on top, seed into that. The topsoil calculator sizes the growing layer.
A pool fill, worked
A 15 by 30 foot pool, 5 feet average depth, coming out: 2,250 cubic feet is 83 yards compacted in place, so order about 104 loose, seven to ten tandem loads. This is also the job where free fill is worth chasing: excavation companies pay to dump clean dirt, and a "you dig it, you take it" listing nearby can cut the material cost to zero. Confirm it's clean (no concrete chunks, no debris, no organics) before the first truck tips.
Placement rules that save regrading
- Compact in 6-inch lifts, not one deep dump. Even a rented plate compactor only densifies the top few inches per pass.
- Keep fill 6 inches below siding and sloped away from the house, about an inch of fall per foot for the first 6 feet.
- Never bury wood, stumps, or sod under structural fill. They rot into voids, and the void becomes a sinkhole with your shed on it.
- Around utilities, hand-place the first foot. Call 811 before any fill job that involves digging or heavy trucks over lines.
Common questions
A tandem-axle dump carries 10 to 14 cubic yards; a single-axle around 5 to 7. Ask what the truck holds when you order, because two 7-yard loads and one 14-yard load price out differently.
Fill dirt is subsoil, no organic matter, which is why it compacts solid and holds grade. Topsoil is the living top layer for planting. Fill for structure, topsoil for growing, never swapped.
Often $5 to $25 a yard delivered, and sometimes free from excavation companies looking to dump clean fill nearby. Quality varies with the price. For anything structural, ask for select fill and confirm it's debris-free.
If anything will sit on it, yes, in 6-inch layers, ideally with a plate compactor. Loose fill settles for years. For a garden berm nobody walks on, loose is fine, and the toggle above handles both cases.
Estimates for planning. Verify against your supplier's units and your local building codes before ordering or building. For anything structural, follow your engineer or local code.