How much gravel, stone or sand do you need?
Aggregate is sold in two different ways, which is why the answer has two different units. Loose material is measured by volume — cubic yards in the US, cubic metres elsewhere — while the truck that delivers it is usually billed by weight, in US tons or metric tonnes. This calculator produces both, plus the coverage figure that tells you how far one yard or one ton actually goes at your chosen depth.
The three steps behind every answer
- 1. Area. Rectangle: length × width. Circle: π × radius². Triangle: base × height ÷ 2. Enter feet and inches, yards, metres or centimetres — the calculator converts internally.
- 2. Volume. Area × depth. Convert the depth to feet first: 3 in is 0.25 ft, 4 in is 0.333 ft, 6 in is 0.5 ft. One cubic yard is 27 ft³, which is 0.765 m³.
- 3. Weight. Volume × bulk density. Loose densities run about 2,600–2,800 lb per cubic yard for gravel and crushed stone (1.30–1.40 US tons/yd³, roughly 1,550–1,660 kg/m³), about 3,200 lb/yd³ for wet sand, and around 1.30 t/yd³ for river rock.
Depths that actually work
A gravel path needs 2–3 in of stone over a compacted base; a driveway wants 4–6 in of crushed stone over 4–6 in of larger base material; a decorative bed of pea gravel or river rock is usually 2–3 in deep; a French drain or dry well is filled by volume rather than by a neat layer. Order 5–10% extra for compaction and settlement, especially on a driveway where the first rain and the first few tyre passes will pack the stone down.
Bags, super sacks or a dump truck?
Half-cubic-foot bags (about 50 lb) make sense for a few square metres or a patch job; a one-yard super sack is the sweet spot for most garden projects; and once you pass two or three cubic yards, a tipper delivery is the only sane option. Whatever you buy, ask the yard for their density figure — the same truckload can be 10–20% heavier wet than dry, which changes your tonnage and your bill.
Frequently asked questions
How many tons are in a cubic yard of gravel?
About 1.30 to 1.45 US tons for most gravel and crushed stone, because a cubic yard of loose aggregate weighs roughly 2,600–2,900 lb. Pea gravel sits near the bottom of that range (about 1.30 t/yd³), while wet sand can reach 1.60 t/yd³ — always confirm with the supplier for the material you are actually buying.
How much gravel do I need for a driveway?
Measure the driveway in feet, multiply length by width for the area, and plan for 4 inches of top stone (plus a separate 4–6 inch base layer of larger stone). A 10 ft × 20 ft driveway at 4 inches needs 2.47 cubic yards, or about 3.5 US tons of crushed stone — this calculator gives you both numbers plus a 5–10% compaction allowance.
How deep should gravel be for a path or a decorative bed?
Two to three inches of pea gravel or river rock is enough for a walking path or a decorative bed; go to four inches on soft ground or where you walk daily. Deeper is not better: too much rounded stone rolls underfoot, and weed growth comes from the soil below rather than from the stone depth.
How do I convert square feet of coverage into cubic yards?
Multiply the area by the depth in feet and divide by 27. For 100 ft² at 3 inches: 100 × 0.25 = 25 ft³, and 25 ÷ 27 = 0.93 cubic yards. This calculator does that conversion and also tells you the reverse — how many square feet one cubic yard or one ton will cover at your depth.
Should I add extra for compaction?
Yes, 5 to 10% is normal. Loose aggregate settles as it is compacted and trafficked, and a driveway can lose 10% of its depth in the first season. Use 5% for a decorative bed, 10% for a compacted driveway, and up to 15% if the ground beneath is soft or uneven.
Why do different calculators give different tonnage for the same volume?
Because bulk density is not a fixed number. It depends on the rock type, the grading (how the sizes are mixed), how much moisture the stone is holding and how well settled the pile is; loose material also sits about 40% void by volume. Charts give planning figures, and the scale ticket from your supplier is the ground truth.