GRAVEL CALCULATOR
How it works
A 20 ft × 10 ft driveway pad, 4 inches deep, plus 10% for spreading.
- Convert the depth to feet: 4 in ÷ 12 = 0.333 ft.
- Volume: 20 × 10 × 0.333 = 66.67 ft³, which is 2.47 yd³.
- Add 10% waste: 2.47 × 1.10 = 2.72 yd³.
- Weight: 2.72 yd³ × 2,835 lb/yd³ ÷ 2,000 = 3.85 tons.
2.72 cubic yards — about 3.85 tons.
Constants
| Constant | Value |
|---|---|
| Gravel density | 2,835 lb/yd³ |
| Cubic feet per cubic yard | 27 ft³ |
| Pounds per US ton | 2,000 lb |
SOURCE — gravel, dry loose: 2,835 lb/yd³ (range 2,700–3,000 dry; 3,100–3,400 compacted or wet).
SOURCE — 1 yd³ = 27 ft³, by definition.
SOURCE — 1 US short ton = 2,000 lb, by definition.
Quick answers
A 20 ft × 10 ft area at 4 inches deep takes 2.47 cubic yards of gravel, or 2.72 yards with 10% added for spreading and settling.
One cubic yard of dry gravel weighs about 2,835 lb, so a yard is roughly 1.42 tons. Wet or compacted gravel runs heavier, up to 3,400 lb per yard.
Gravel is sold both by the yard and by the ton. Ask which your supplier uses before ordering — the same pile has two different numbers on it.
For a driveway base, 4 inches of compacted gravel is the usual minimum; heavy vehicles want 6 to 8 inches over a properly prepared subgrade.
To convert cubic yards of gravel to tons, multiply by 1.42. To go the other way, divide tons by 1.42.
FAQ
How many tons of gravel do I need?
Work out the volume in cubic yards, then multiply by 1.42. A 20 ft × 10 ft pad at 4 inches deep is 2.47 yd³, which is about 3.5 tons — or 3.85 tons once you add 10% for spreading.
How much gravel do I need under a slab?
Four inches of compacted gravel under a residential slab is the common specification. For a 10 ft × 12 ft slab that is 1.48 cubic yards, or about 2.1 tons.
How many cubic yards is a ton of gravel?
About 0.7 cubic yards, using a dry loose density of 2,835 lb per yard. A ton is a weight and a yard is a volume, so the ratio changes with moisture and compaction.
Is crushed stone the same as gravel for this calculation?
Close enough for ordering. Crushed stone runs slightly heavier than round river gravel — typically 2,700 to 3,000 lb per yard dry — so treat the result as an estimate and confirm the density with your yard.
How deep should gravel be for a driveway?
Four inches for cars over a stable subgrade, and 6 to 8 inches where trucks turn or the ground is soft. Deeper layers are usually placed in two lifts and compacted separately.
Why does the tonnage differ between suppliers?
Because density does. Dry loose gravel is around 2,835 lb per yard; wet or compacted material can reach 3,400. This page uses the dry loose figure, so wet material will weigh more than the estimate.