How Much Gravel Do I Need? A Simple Way to Estimate Yards and Tons
Multiply length × width × depth in feet, then divide by 27 to get cubic yards. Crushed rock weighs roughly 1.4 tons per cubic yard, so multiply by about 1.4 to estimate tons. Add 10 to 15 percent extra to allow for compaction and uneven ground.
3/4-Inch Minus vs. 1-1/2-Inch Minus vs. Pea Gravel: Which Rock Goes Where?
Use crushed “minus” rock, like 3/4″ minus, anywhere vehicles drive, because its fines let it compact into a firm surface. Use larger 1-1/2″ or 3″ minus as a base on soft ground. Save pea gravel for paths and play areas, and use clean drain rock, which has no fines, wherever water needs to pass through.