Outdoor, Deck & Fence
Gravel Calculator
Cubic yards and tons of gravel, crushed stone or sand for driveways, paths and drainage.
Inputs
Results
Adjust the inputs to see your result.
About this calculator
Aggregates are sold by the ton but measured by volume, and density varies by material — a cubic yard of pea gravel weighs about 1.3 tons, crushed stone closer to 1.4. This calculator handles the conversion for your chosen material and depth, including compaction allowance.
What this number means
Aggregates live in two unit systems at once: you measure the job in cubic yards, but the yard sells by the ton and the truck is weighed. The conversion between them is the material's density, and it is not universal — a cubic yard of crushed stone weighs about 1.4 tons, pea gravel nearer 1.3, and wet sand can exceed both. Picking the right material in the calculator is what makes the tonnage honest.
The order figure adds a compaction allowance because loose stone is not finished stone: a driveway layer rolled and trafficked settles measurably, and topping up a finished driveway with a second small delivery costs more than ordering the extra 5% up front.
The formula
- Cubic yards = Area (sq ft) × Depth (in) ÷ 324
- Tons = Cubic yards × density (pea gravel 1.30 · crushed stone 1.40 · river rock 1.35 · sand 1.35 · decomposed granite 1.45 tons per cu yd)
- Tons to order = Tons × (1 + compaction %)
- Coverage check: 1 ton of crushed stone covers roughly 55 sq ft at 4 in deep
Worked example
A 12 × 30 ft driveway, 4 in of crushed stone.
- Volume = 360 sq ft × 4 ÷ 324 = 4.44 cu yd
- Weight = 4.44 × 1.40 = 6.22 tons
- With 5% for compaction: 6.5 tons to order (yards round to the half ton)
Assumptions and limitations
- Densities are for loose, dry material as delivered. Rain-soaked stockpiles weigh more per yard — if your delivered tonnage looks high after a wet week, that is water, not short measure.
- Depth is the finished, compacted depth. If you are placing in two lifts, this calculator gives the total; order in two deliveries only if the job is phased.
- Driveway estimates assume the excavation and base are separate line items — road base/crusher run uses the same maths with the crushed-stone density.
- Bagged gravel (0.5 cu ft bags) is roughly 54 bags per cubic yard — viable for a path, painful for a driveway. The calculator reports yardage and tonnage; multiply cu ft by 2 for the 0.5 cu ft bag count.
Frequently asked questions
A typical single driveway (12 × 30 ft) at 4 in of crushed stone needs about 6.5 tons ordered. The full chain: 360 sq ft × 4 in = 4.44 cu yd, × 1.40 tons per yard = 6.22 tons, plus 5% compaction. Enter your dimensions and material above for your figure.
About 0.71 cu yd for crushed stone (1 ÷ 1.40), and 0.77 for pea gravel (1 ÷ 1.30). There is no single answer — it depends on the material density, which is why the calculator asks what you are buying.
Crushed stone at 4 in deep: roughly 55 sq ft per ton. At 2 in (paths and top-ups) about 110 sq ft per ton. Coverage halves as depth doubles — depth is the number people underestimate.
Usually water. A stockpile after rain can carry several percent extra weight, and you pay by the ton. Volume (cubic yards) is the stable measure of what you got; if a dispute matters, measure the pile, not the ticket.
Four inches of surface stone over a compacted base is the residential norm; 5–6 in total build-up for soft ground. Decorative paths need only 2–3 in. Deeper is not better on top — without a base, extra loose stone just ruts and migrates.