Gravel Calculator — Cubic Feet
Choose your gravel type, enter dimensions and see cubic feet, cubic yards and weight in tons.
Gravel Types
Pea gravel — small, rounded; pathways, playgrounds, drainage.
Crushed stone (¾") — angular; driveways, base layers, French drains.
River rock — large, smooth; decorative beds, dry creeks.
Decomposed granite — fine; patios, pathways that compact firm.
Lava rock — porous, lightweight; decorative mulch.
Recommended Depths
| Application | Depth |
|---|---|
| Walking path | 2–3 inches |
| Driveway (top layer) | 4 inches |
| Driveway (full build) | 6–8 inches (with base) |
| French drain | 6+ inches |
| Decorative bed | 2 inches |
| Playground | 9–12 inches |
Weight Conversion
Most gravel weighs 95–110 lb per cubic foot. To convert cubic feet to tons: ft³ × density ÷ 2000. A cubic yard of crushed stone weighs about 2,700 lbs (1.35 tons).
Lava rock is the exception at ~50 lb/ft³ — half the weight of standard gravel.
Worked Example
A 30 ft × 12 ft driveway at 4 inches of crushed stone: 30 × 12 × 0.333 = 120 ft³ = 4.44 yd³. Weight: 120 × 100 = 12,000 lbs = 6 tons.
Gravel vs Soil and Mulch Coverage
Gravel, soil and mulch all use the same area × depth formula to reach cubic feet, but the numbers you'll see quoted differ because the materials pack at different depths for different jobs. Gravel for a driveway sits 4–6 inches deep; mulch for a garden bed sits 2–4 inches deep; topsoil for a lawn sits 2–4 inches deep but for a raised bed can run 8–12 inches. If your project combines a gravel base layer with a soil or mulch top layer, calculate each layer's cubic feet separately with its own depth, then add the two volumes together for the total material order.
Frequently Asked Questions
How deep should driveway gravel be?
4–6 inches for driveways, 3 inches for walking paths, 6 inches for drainage applications.
How much does a cubic yard of gravel weigh?
About 2,500–3,000 pounds (1.25–1.5 tons), depending on the type and moisture content.
How many cubic feet in a ton of gravel?
Approximately 20 cubic feet per ton (assuming ~100 lb/ft³ density).
What's the cheapest gravel?
Crushed gray limestone is typically the cheapest at $20–$40 per cubic yard delivered.
How much gravel for a 20x20 driveway?
400 sq ft × 6 in (0.5 ft) = 200 ft³ = 7.4 cubic yards.
Should I use landscape fabric under gravel?
Yes for paths and driveways — it stops gravel from sinking into soil and blocks weeds.
How heavy is pea gravel?
About 96 pounds per cubic foot or roughly 1.3 tons per cubic yard.
Pea gravel vs crushed stone?
Pea gravel is rounded (good for paths, playgrounds); crushed stone has angular edges that lock together (better for driveways).