How to use the gravel calculator
- Enter the area as length and width, a circle, a triangle, or a known total.
- Enter the depth of the gravel layer you are calculating. For a layered driveway, run the calculator once for each layer.
- Select a gravel type. This loads a typical bulk density. Aggregate suppliers sell by the ton, so density is what converts your yards into tons.
- Read tons and cubic yards side by side. Enter the price per ton or per yard to estimate cost.
Gravel formula: from cubic yards to tons
Cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27
Tons = cubic yards × density (tons per yd³)
To go the other way, cubic yards = tons ÷ density. A quick rule of thumb: one cubic yard of typical gravel weighs about 1.4 tons, so 10 tons is roughly 7 cubic yards.
Typical gravel densities
- Crushed stone #57 (about 3/4 inch, washed): ~100 lb/ft³, 1.35 t/yd³
- Dry gravel, general: ~105 lb/ft³, 1.42 t/yd³ — the value given in The Engineering ToolBox's density table
- Crusher run / road base (stone plus fines): ~110 lb/ft³, 1.49 t/yd³ loose; fines fill the gaps, so it is heavier
- Wet gravel: ~125 lb/ft³, 1.69 t/yd³ (The Engineering ToolBox)
Densities vary by quarry and moisture. Treat these as planning figures and ask the yard for its own tons-per-yard number before you pay for a load.
Worked example: gravel driveway
A driveway is 50 ft long and 12 ft wide. You want a 4-inch top layer of #57 crushed stone, with 10% extra.
- Area: 50 × 12 = 600 sq ft
- Volume: 600 × 4 ÷ 12 = 200 cu ft; with 10% = 220 cu ft
- Cubic yards: 220 ÷ 27 = 8.15 yd³
- Tons at 100 lb/ft³: 220 × 100 ÷ 2,000 = 11.0 tons
A typical single-axle dump truck carries roughly 6–10 tons, so this may be one large load or two smaller ones. Ask about truck capacity when you order.
How a gravel driveway is layered
- Subgrade: remove topsoil and organic material, then compact the soil. Geotextile fabric on soft clay soils keeps stone from sinking.
- Base layer, 4–6 inches: larger crushed stone (such as #3) or crusher run, compacted.
- Top layer, 2–4 inches: #57 stone, crusher run, or a decorative gravel. Crown the surface slightly so water runs off.
Compacted crusher run settles noticeably. If you are calculating a layer that will be compacted with a plate compactor or roller, the paver base calculator includes a compaction allowance. For a cheaper base, see the crushed concrete calculator.
Tips to avoid ordering mistakes
- Measure depth after excavation at several points and use the average.
- Round up to the supplier's minimum increment (often half or whole tons) rather than down.
- Have the truck spread the load ("tailgate spreading") if your driveway is long; it saves hours of raking.
Frequently asked questions
How many tons of gravel are in a cubic yard?
Typically 1.35 to 1.5 tons for dry gravel and crushed stone, and up to about 1.7 tons when wet. Use 1.4 as a rough planning figure.
How many cubic yards are in a ton of gravel?
About 0.7 cubic yards per ton at 1.4 tons per yard. Divide tons by the density in tons per cubic yard.
How much gravel do I need for a driveway?
Multiply length by width by depth in feet and divide by 27 for cubic yards. A 50 × 12 ft driveway at 4 inches needs about 7.4 cubic yards, or about 10 tons of crushed stone, before waste.
How deep should driveway gravel be?
Plan 8–12 inches in total over prepared soil: a 4–6 inch base of larger stone or crusher run and a 2–4 inch top layer.
How much area does a ton of gravel cover?
At 1.4 tons per yard, one ton is about 19 cubic feet, which covers roughly 77 sq ft at 3 inches deep, 58 sq ft at 4 inches, or 39 sq ft at 6 inches.