Gravel Calculator
Use this gravel calculator to work out how much gravel you need for a driveway, patio, path, garden bed or base layer. Enter a rectangle, circle or L-shape and a depth, pick the type of gravel, and it gives the amount in cubic yards and tons, plus the cost if you add your supplier’s price.
Gravel calculator
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How to calculate how much gravel you need
Every gravel job comes down to the same three steps. The calculator does them for you, but it helps to know what it is doing so you can sense-check the result.
- Area and volume: work out the area (length × width for a rectangle; 3.1416 × diameter × diameter ÷ 4 for a circle; two rectangles added together for an L-shape). Multiply by the depth in inches ÷ 12 to get cubic feet, then divide by 27 to get cubic yards.
- Weight: cubic yards × the gravel’s density (tons per cubic yard) gives tons. Most gravel weighs about 1.3 to 1.5 tons per cubic yard.
- Allowance: add a margin for compaction, uneven ground and spillage, often around 10%, so you don’t run short.
Worked example: a 20 × 10 ft patio area at 3 inches deep is 200 square feet × 0.25 ft = 50 cubic feet, or 1.85 cubic yards. In #57 crushed stone at 1.4 tons per cubic yard, that is about 2.6 tons. With a 10% allowance, it is about 2.04 cubic yards or 2.85 tons, so you would order 3 tons.
How many tons of gravel per 100 square feet?
This table uses the same densities as the calculator. Figures are before any allowance. Your supplier’s density may differ, especially for wet or locally quarried stone, so check theirs before you order.
| Gravel type | Density (tons/yd³) | 2 in | 3 in | 4 in |
|---|---|---|---|---|
| Crushed stone (#57) | 1.40 | 0.86 | 1.30 | 1.73 |
| Class 5 / road base | 1.50 | 0.93 | 1.39 | 1.85 |
| Pea gravel | 1.35 | 0.83 | 1.25 | 1.67 |
| River rock | 1.45 | 0.90 | 1.34 | 1.79 |
| Decomposed granite | 1.30 | 0.80 | 1.20 | 1.60 |
| Crushed concrete (recycled) | 1.30 | 0.80 | 1.20 | 1.60 |
How much does a ton of gravel cover?
Square feet covered by one ton = 324 ÷ (density × depth in inches). For #57 crushed stone, one ton covers about 116 sq ft at 2 inches, 77 sq ft at 3 inches and 58 sq ft at 4 inches. Lighter materials such as decomposed granite cover a little more, and road base a little less. The calculator shows this figure for whatever material and depth you enter.
What depth of gravel should I use?
Depth depends on what the gravel has to carry. Decorative cover and walking paths usually need only a few inches. Areas that carry vehicles need a deeper, compacted base, often laid in layers. For driveways, see how thick a gravel driveway should be or use the gravel depth calculator. For a base under the surface layer, use the driveway base gravel calculator.
Check with your supplier: stone sizes, names and densities vary by region and quarry. Ask what density they use and whether they sell by the ton or by the cubic yard, then enter that in the calculator.
Cubic yards or tons: which should I order?
Order in whatever unit your supplier sells in. Landscape yards often sell by the cubic yard, while quarries usually sell by the ton. The calculator shows both. To convert between them for a specific material, use the tons to cubic yards calculator or read how many yards are in a ton of gravel.
Related calculators and guides
- Gravel driveway calculator (one layer or base + surface)
- Gravel cubic yard calculator
- Pea gravel calculator (with bag counts)
- Gravel driveway cost calculator
- Types of gravel for driveways
Frequently asked questions
How do I calculate how much gravel I need?
Multiply length × width in feet by depth in inches, divide by 12 to get cubic feet, then divide by 27 to get cubic yards. Multiply cubic yards by the gravel’s density, usually 1.3 to 1.5 tons per cubic yard, to get tons. Add an allowance of around 10%.
How many tons of gravel do I need for 100 square feet?
At 3 inches deep, about 1.2 to 1.4 tons depending on the type of gravel. At 2 inches it is about 0.8 to 0.9 tons, and at 4 inches about 1.6 to 1.85 tons. See the table above for each material.
How much does a cubic yard of gravel weigh?
Most gravel weighs between about 1.3 and 1.5 tons per cubic yard (2,600 to 3,000 lb). Denser stone such as road base is at the top of that range, and lighter materials such as decomposed granite are at the bottom.
Can I use this gravel calculator for round or L-shaped areas?
Yes. Choose Circle and enter the diameter, or choose L-shape and split the area into two rectangles that don’t overlap. For other shapes, measure the area as several rectangles and add the results.