#57 Gravel Calculator
#57 gravel is clean, ~3/4" crushed stone with the fines removed, so it drains freely — perfect for French drains, driveways and bases under concrete and pavers. 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 (1.74 US tons) of #57 gravel.
Estimates only. Densities vary by moisture, compaction and supplier — confirm quantities before ordering.
What is #57 gravel?
#57 gravel is crushed stone screened to roughly 3/4 inch (about 19 mm) with the fine particles removed. That makes it a clean, uniform, 'open-graded' aggregate with lots of gaps between the stones.
What is #57 gravel used for?
Because it drains freely, #57 is the standard for French drains, drainage behind retaining walls, pipe bedding, and as a base under concrete and pavers. It's also popular for driveways, though it doesn't pack into a hard surface on its own.
How much does #57 gravel weigh?
A cubic yard of #57 gravel weighs about 1.28 US tons — roughly 1520 kg/m³, or about 95 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 | ~253 sq ft | 324 sq ft |
| 2 inches | ~126 sq ft | 162 sq ft |
| 3 inches | ~84 sq ft | 108 sq ft |
| 4 inches | ~63 sq ft | 81 sq ft |
| 6 inches | ~42 sq ft | 54 sq ft |
Based on about 1520 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
Does #57 gravel compact?+
Not into a solid surface — with no fines it stays loose and open, which is exactly why it drains so well. For a firm base, use road base or crusher run underneath and #57 on top or for drainage.
How much #57 gravel for a French drain?+
Measure the trench length × width × depth and enter it above. A common French drain is about 12 inches deep and 6–12 inches wide, wrapped in filter fabric.
What does #57 mean and what size is it?+
The '#57' is a sizing spec, not a rock type — it means the stone was screened to roughly 3/4 inch with the fines (dust and sand) washed out. That's why it's 'clean,' with lots of gaps for water to run through. You'll see #57 in granite, limestone or river gravel depending on the quarry; the number tells you the size and that it drains, not what it's made of.
Can you use #57 gravel for a driveway?+
You can, and plenty of people do because it drains well and looks clean — but it never packs into a hard surface, so it stays loose underfoot and tires push it around. If you want #57 on a driveway, run it over a compacted road-base layer and edge it, or plan to rake and top it up. For a firm, low-maintenance driveway on its own, road base or crusher run is the better call.