Gravel is sold by the ton (or by the cubic yard, which the yard converts to tons), so a gravel estimate is really two calculations: the volume of the bed, and the weight of that volume for the stone you picked. This calculator does both, adds a settling allowance, and gives a bag count for small jobs.
The formula
Densities vary more than people expect. A cubic yard of pea gravel weighs about 1.35 tons; angular crushed stone packs tighter at about 1.45 tons; dense crusher run reaches 1.5 tons. If your supplier quotes a different density for their material, choose the closest type — or work backwards from their figure: the exact cubic yards on this page never change, only the weight does.
How deep should gravel be?
For a driveway, 4–6 inches total over a compacted base (often in two layers: coarse stone below, finer on top). Garden paths do fine at 2–3 inches over landscape fabric. Drainage beds and French drains usually want 6 inches or more around the pipe. Deeper is not better for paths — beyond 3 inches loose gravel starts to feel unstable underfoot.
Worked example
A 10 ft × 10 ft pad at 3 inches deep: volume = 100 × 0.25 = 25 ft³ = 0.93 yd³. At the standard gravel density of 1.40 t/yd³ that is 1.30 tons exact — and 1.43 tons with a 10% settling allowance, or 50 × 0.5 ft³ bags if you are bagging it.
How to use this tool
- Measure the length and width of the area and choose units.
- Enter the depth you plan to spread — compacted depth, not loose depth.
- Pick the gravel type closest to what you are buying; the density drives the tonnage.
- Keep the 10% settling extra for driveways, lower it for fabric-covered paths.
- Order by the ton for anything over a yard; use the bag count for small patches.
Delivery reality check
One ton of gravel covers roughly 100 ft² at 1 inch deep, or about 35 ft² at a full 3 inches once compacted — a useful sanity check on any quote. If your order is over 2–3 tons, delivery usually beats bagged gravel on price by a wide margin, and a truck can often spread the load as it dumps if you ask when ordering.