Cubic Yard Calculator
Convert a rectangular project measured in feet and inches into cubic feet and cubic yards, then add a practical material allowance.
What does the cubic yard calculator calculate?
Multiply length in feet by width in feet and depth in feet to get cubic feet, then divide by 27 for cubic yards. Because depth is entered in inches here, divide it by 12 first. Add waste for settlement, grading variation, and delivery limitations.
Rectangular volume in cubic yards
Dividing inches by 12 converts depth to feet. The three dimensions then produce cubic feet, and dividing by 27 converts cubic feet to cubic yards because one cubic yard is 3 × 3 × 3 feet.
How to measure for an accurate estimate
- Measure the longest and widest limits of the material area in feet.
- Take several depth readings and use an average rather than assuming perfectly level ground.
- Break curved or irregular areas into smaller rectangles and calculate them individually.
- Measure compacted finished depth for specifications, then account separately for expected settlement.
Gravel base volume
A 20 ft by 10 ft rectangular base needs 4 inches of material plus 10% extra.
20 × 10 × (4 ÷ 12) ÷ 27 = 2.47 cu yd; with 10% extra, order 2.72 cu yd.Before you purchase material
- Ask whether the supplier measures loose, compacted, or installed volume.
- Confirm minimum delivery quantity, partial-yard increments, and truck access before ordering.
- For heavy products, verify that the driveway and unloading area can support the delivery truck.
- Do not use one universal waste rate; soil settling, gravel compaction, and concrete placement differ.
Common questions
How many cubic feet are in one cubic yard?
One cubic yard contains 27 cubic feet. A cubic yard is a cube measuring three feet long, three feet wide, and three feet high, so its volume is 3 × 3 × 3 = 27 cubic feet.
How many square feet does one cubic yard cover?
Coverage depends on depth. One cubic yard covers about 81 square feet at four inches deep, 108 square feet at three inches, or 324 square feet at one inch. Actual coverage changes with compaction and surface variation.
Should I round cubic yards up or down?
Round up to the supplier’s available increment because a short load can interrupt work and cost another delivery fee. First add an appropriate allowance, then round once. Avoid repeatedly rounding intermediate measurements, which can inflate the result.
How do I calculate cubic yards for a circular area?
Find the circle’s area using π × radius², multiply by depth in feet, and divide the resulting cubic feet by 27. Use radius, not diameter, and take multiple depth readings when the excavation is uneven.
Sources and reference standards
- National Institute of Standards and Technology — SI Units: LengthPrimary federal reference for customary-to-metric length relationships and unit definitions.