Gravel calculator
Cubic yards of gravel for a rectangular area and depth, plus tons for a density you choose.
How it's calculated
Suppliers usually sell gravel by the cubic yard. The calculator works out the volume of a rectangular area at an even depth, adds any waste allowance you enter, and converts to tons only when you pick a density.
cubic feet = length (ft) × width (ft) × depth (in) ÷ 12 × (1 + waste %)
cubic yards = cubic feet ÷ 27
short tons = cubic feet × density (lb/ft³) ÷ 2,000
Worked example
A 20 ft × 12 ft area at 4 in deep is 20 × 12 × 4 ÷ 12 = 80 ft³, which is 80 ÷ 27 = 2.96 yd³. At the FHWA compacted aggregate base value of 139 lb/ft³, that is 80 × 139 ÷ 2,000 = 5.56 tons.
The FHWA value is for compacted base material. Loose decorative or pea gravel usually weighs less per cubic foot. For a purchase, use the density your supplier gives.
Sources
- 27 cubic feet = 1 cubic yard: NIST Handbook 44, Appendix C.
- Aggregate base 139.0 lb/ft³: FHWA Central Federal Lands, Application Rates and Weights for Estimating Purposes (2009).
Estimates only. Order a little extra and confirm quantities with your supplier.