How to Calculate Gravel and Stone
Gravel is typically sold by the ton, so you'll need to convert your volume calculation. First calculate cubic yards, then multiply by the density of your stone type (usually 1.3–1.6 tons per cubic yard).
Gravel Formula:
Cubic Yards = (Length × Width × Depth in ft) ÷ 27
Tons = Cubic Yards × Density
Example: 20×10 ft at 4 inches deep with crushed stone (1.5 density) = (200 × 0.333) ÷ 27 × 1.5 = 3.7 tons
Gravel Depth Guide by Project Type
| Project | Recommended Depth |
|---|
| Decorative landscape beds | 2–3 inches |
| Walkway / path | 3–4 inches |
| Residential driveway (top layer) | 4 inches |
| Driveway (base layer) | 6–8 inches |
| French drain | Fill to grade |
Gravel Cost by Type
| Stone Type | Cost per Ton | Best Use |
|---|
| Pea Gravel | $25–$45 | Walkways, playgrounds, drainage |
| Crushed Stone (#57) | $28–$50 | Driveways, drainage, base layer |
| River Rock | $40–$80 | Decorative beds, dry creek beds |
| Limestone Gravel | $30–$55 | Driveways, paths, base |
| Marble Chips | $75–$150 | Premium decorative |
Gravel Installation Tips
- Install landscape fabric before adding gravel to suppress weeds effectively
- Use edging (steel, aluminum, or plastic) to contain the gravel
- Compact in 2-inch layers using a plate compactor for driveways
- For decorative beds, rake smooth and top up annually as gravel settles
- Add 10% to your calculation to account for settling and compaction
Frequently Asked Questions
How many tons of gravel do I need for a driveway?▾
For a typical residential driveway (20 ft wide × 50 ft long) at 4 inches of crushed stone, you'll need approximately 12 tons. For a gravel base layer at 6 inches, add another 18 tons. Most driveways need 10–20 tons total depending on length and width.
How much area does a ton of gravel cover?▾
At 2 inches deep, 1 ton of gravel covers approximately 100 sq ft. At 3 inches deep, about 65 sq ft. At 4 inches, roughly 50 sq ft. Coverage varies by stone density and type.
What is the best gravel for a driveway?▾
Crushed stone (#57 or #21A) is the most popular driveway material — it compacts well, drains properly, and lasts for years. Avoid rounded pea gravel for driveways as it shifts underfoot and under tires.
Do I need landscape fabric under gravel?▾
Yes, for decorative beds. Landscape fabric under gravel prevents weeds from growing up through the stone. For driveways, a geotextile fabric between the sub-base and gravel helps prevent the layers from mixing and extends the driveway's life.
How deep should pea gravel be for a walkway?▾
Lay pea gravel 3–4 inches deep for a stable walkway. Less than 2 inches will scatter easily and look thin. Install edging to contain it, and compact slightly with a plate compactor or tamper.