How to Calculate How Much Crushed Stone I Need | Home ...
Multiply your area by the depth in feet that you want your crushed stone. For example, a rectangular walkway that is 40 feet long and 2 feet wide is 80 square feet. To put a depth of crushed stone at 4 inches deep, convert the inches in depth to feet by dividing 4 by 12 to get feet. Multiply the area in feet times the depth in feet.