Cubic Yard Calculator for Concrete
Enter length, width and depth to get cubic yards and cubic feet of concrete, and what that much ready-mix costs at US prices.
Enter sizes greater than zero.
Prices are US national ranges from published sources, checked September 23, 2026. Where the numbers come from.
How to calculate cubic yards
Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27
Depth is usually given in inches, so divide it by 12 first. A 12 × 20 ft area poured 4 inches deep is 12 × 20 × 0.333 = 80.0 cubic feet, or 2.96 cubic yards.
For round shapes such as post holes and columns, use the footing calculator. For steps, use the stairs calculator.
How far a yard goes
| Thickness | Area covered by 1 cu yd | Ready-mix per 100 sq ft |
|---|---|---|
| 3 in | 108.0 sq ft | $150–$180 |
| 4 in | 81.0 sq ft | $200–$240 |
| 5 in | 64.8 sq ft | $245–$300 |
| 6 in | 54.0 sq ft | $295–$360 |
| 8 in | 40.5 sq ft | $395–$480 |
Ready-mix at $160–$195 per cubic yard[1], before delivery and short-load fees.
How much concrete do I need?
- Measure the area in feet. Split an L-shape into two rectangles and add them.
- Decide the depth. Measure the forms or the excavation, not the plan. Depth errors are the usual reason people run short.
- Calculate the volume with the calculator above.
- Add extra for spillage and uneven ground; the calculator defaults to 10%.
- Round up to what your supplier sells. Ask them their minimum order and increment.
Frequently asked questions
How do I calculate cubic yards of concrete?
Multiply length × width × depth in feet to get cubic feet, then divide by 27. Convert inches to feet by dividing by 12: a 4 inch slab is 0.333 ft deep.
How many square feet does a yard of concrete cover?
At 4 inches thick, one cubic yard covers 81 square feet. At 6 inches it covers 54 square feet.
How many cubic feet are in a cubic yard?
27. A cubic yard is 3 ft × 3 ft × 3 ft.
How much does a cubic yard of concrete cost?
Ready-mix runs about $160–$195 per cubic yard in the US, before short-load and delivery fees. See concrete price per yard.
Sources
- Concrete Network, Concrete prices, updated 2026-07-14. Checked September 23, 2026.