Crushed Stone Calculator
Crushed stone is angular quarried rock that locks together and compacts firm — the workhorse for driveways, bases under pavers and slabs, and drainage. Work out exactly how much you need below.
Sets a typical depth — tweak anything below.
For a 20 ft × 10 ft area at 2 in deep, order about 1.36 cubic yards (1.83 US tons) of crushed stone.
Estimates only. Densities vary by moisture, compaction and supplier — confirm quantities before ordering.
What is crushed stone?
Crushed stone is quarried rock mechanically crushed into angular, sharp-edged fragments. The jagged faces interlock and compact into a firm, stable layer — unlike smooth, rounded gravel.
What is crushed stone used for?
It's the workhorse aggregate for driveways, road base, and bases under pavers, slabs and footings, plus drainage. The angularity is what makes it stay put and carry weight.
How much does crushed stone weigh?
A cubic yard of crushed stone weighs about 1.35 US tons — roughly 1602 kg/m³, or about 100 lb/ft³. Moisture and compaction shift this, so the calculator applies this density and lets you change it in the extra options if your supplier quotes a different figure.
Coverage by depth
| Depth | Coverage per ton | Coverage per cubic yard |
|---|---|---|
| 1 inch | ~240 sq ft | 324 sq ft |
| 2 inches | ~120 sq ft | 162 sq ft |
| 3 inches | ~80 sq ft | 108 sq ft |
| 4 inches | ~60 sq ft | 81 sq ft |
| 6 inches | ~40 sq ft | 54 sq ft |
Based on about 1602 kg/m³. Actual coverage varies with compaction and moisture.
Common mistakes to avoid
- Guessing the depth. Too shallow and the material shifts and shows the ground beneath. Most surface layers want 2–4 inches; load-bearing bases are built up thicker.
- Forgetting to convert inches to feet. Depth is quoted in inches but volume math is in feet — 4 inches is 0.33 ft, not 4. The calculator handles this, but hand estimates often don't.
- Skipping the waste allowance. Ground is never perfectly flat and material settles once it's placed. Order 5–10% extra so a small shortfall doesn't trigger a second delivery.
- Using the wrong density. Each material weighs differently, so tonnage can be off by 20%+ if you use a generic figure. Pick the right material and adjust the density if your supplier differs.
- Buying bags for a big job. Bagged material costs far more per cubic yard than bulk. Past roughly one cubic yard, a bulk delivery is almost always cheaper.
Frequently asked questions
What size crushed stone for a driveway?+
A common build is a compacted base of 3/4" crushed stone or road base topped with a finer crushed stone or #57. A total depth of 4–6 inches over a solid subgrade is typical.
Does crushed stone compact?+
Graded crushed stone with fines (like crusher run/road base) compacts into a hard surface. Clean, single-size crushed stone (like #57) locks together but stays open for drainage.
What's the difference between crushed stone and gravel?+
Crushed stone is machine-broken quarry rock with sharp, angular faces; natural gravel is stone worn smooth and round by water. The shape is the whole point — angular crushed stone locks together and holds firm under weight, so it's used for driveways and bases, while smooth gravel shifts and suits decorative beds. In practice many suppliers say 'gravel' loosely for crushed stone too, so ask for the size and shape, not just the word.
Can you put crushed stone directly on dirt?+
For a path or light-use area, yes — lay landscape fabric first so the stone doesn't work into the soil. For anything that carries weight, like a driveway or shed pad, don't: compact a base of road base or larger stone first, then top with the finer stone. Straight onto soft ground it sinks, and you get ruts and low spots within a season.