Volume estimate
How to calculate cubic yards
Multiply length in feet by width in feet and depth in inches, then divide by 12 to get cubic feet. Divide cubic feet by 27 to get cubic yards. The optional allowance is applied to the calculated volume.
Example: A 12 × 10 ft area filled 3 inches deep needs 30 ft³, or approximately 1.11 yd³. With a 10% allowance, the estimate is 33 ft³, or approximately 1.22 yd³.
Planning a concrete pour? Use our Concrete Calculator for slab sections, bag counts and cost estimates.
How do you convert cubic feet to cubic yards?
Divide cubic feet by 27. For example, 54 cubic feet ÷ 27 = 2 cubic yards.
Need the estimated weight as well? Use the Gravel Calculator to convert project dimensions into cubic yards and US tons.
How many cubic yards do I need for a 100-square-foot area?
At 3 inches deep, 100 square feet needs 25 cubic feet, or about 0.93 cubic yards, before extra allowance. At 6 inches deep, the same area needs about 1.85 cubic yards.
Calculate volume when you already know the area
Multiply square feet by depth in inches, then divide by 324. For example, a 240-square-foot bed at 3 inches deep needs 240 × 3 ÷ 324, or about 2.22 cubic yards.
Measure an L-shaped area
Split the outline into two rectangles that do not overlap. Calculate each rectangle at its own depth, then add the volumes. For example, 12 × 10 ft plus 4 × 6 ft at 3 inches deep gives 30 + 6 = 36 cubic feet, or about 1.33 cubic yards.
Buying bags instead of bulk material?
Multiply cubic yards by 27 to get cubic feet, divide by the cubic feet printed on each bag, then round up. For example, 1.5 cubic yards equals 40.5 cubic feet. At 2 cubic feet per bag, buy 21 bags.