Estimate gravel for a driveway — cubic yards and tons — from the length, width, and depth, with adjustable material density.
yd³ = (L × W × depth) ÷ 27; tons = yd³ × density
Driveways usually need 4–6″ of gravel over a compacted base. Volume times density gives the tonnage suppliers sell by.
A proper driveway has a coarse base layer and a finer top layer — estimate each separately.
A 50 x 10 ft driveway at 4 inches deep is 166.7 cubic feet, or 6.2 cubic yards. At 1.4 tons per cubic yard that's about 8.6 tons, plus 5% waste makes about 9 tons.
A durable gravel driveway is usually built in layers: a coarse base course of larger stone, then a finer top course. Calculate each layer's depth separately and order the right material for each — the base might be 4 inches of crushed run and the top 2 inches of finer gravel.
Crushed gravel runs about 1.4 tons per cubic yard. Confirm the exact weight per yard with your supplier.
A 40×12 ft driveway at 4″ deep needs about 6 cubic yards, or roughly 8.3 tons.