One cubic foot of gravel weighs, on average, 330 pounds, or about 150 kilograms. This average weight assumes that the cubic foot of gravel is dry.
Gravel out of water weighs almost half as much as dry gravel. This measurement is for construction-grade gravel, used for building and landscaping purposes. The average particle size for this type of gravel is about 1/4 of an inch. For lighter-grade, smaller-particle sand, the weight is lower. However, gravel with sand added to the aggregate has dramatically increased weight. Dry gravel has a specific gravity, or the ratio of density compared to that of water, of 1.52.