How to calculate how much gravel you need
The math is simple once you have three measurements. Multiply length × width to get the area, then multiply by the depth to get the volume. The only catch is units: depth is usually measured in inches while length and width are in feet, so it has to be converted before everything lines up. This calculator handles that conversion and then turns the volume into the units suppliers actually sell in — cubic yards, tons, and bags.
Recommended depths by project
| Project | Typical depth |
|---|---|
| Garden / flower bed mulch | 2–3 inches |
| Walkway or path | 2–3 inches |
| Patio base | 4 inches |
| Gravel driveway | 4–6 inches (over a base) |
| Drainage / French drain | varies by design |
How many tons in a cubic yard of gravel?
Crushed gravel typically weighs around 1.4–1.5 tons per cubic yard. Sand is heavier at roughly 1.5 tons, and concrete heavier still. Because suppliers sell stone by the ton but you measure your project by volume, this calculator converts between the two using standard material densities so your order matches your hole.
Why order a little extra
Loose material settles and compacts, some is lost to spillage, and uneven ground takes more than a flat calculation suggests. A common rule is to add 5–10% to your calculated amount. For driveways with a sub-base, remember the base layer is a separate calculation from the surface layer.
Frequently asked questions
Is the cost estimate accurate?
It's a starting point. Enter your local price per ton and the calculator multiplies it by the tonnage. Delivery fees, minimum loads, and material grade all affect the final invoice, so confirm with your supplier.
Can I use this for concrete?
Yes — choose the concrete option for a volume estimate. For structural concrete, always confirm with your ready-mix supplier, who will also account for waste and ordering minimums.
Does it work in metric?
Yes. Switch the units toggle to meters and enter all three dimensions in meters; results still show cubic yards and tons since that's how most material is sold.
Gravel calculation example
A 20-by-10-foot area covered 3 inches deep contains 50 cubic feet, or about 1.85 cubic yards. With a 10% allowance, order roughly 2.04 cubic yards. Tonnage varies by density, moisture and stone size, so confirm the final weight with the supplier.
Related landscaping calculators
Plan connected projects with the paver calculator, concrete calculator, or mulch calculator.