Reference & planning

Concrete Yardage Chart

Find a quick starting quantity, then open the calculator for your actual dimensions. These are geometric volumes before waste or supplier order rounding. The table does not recommend a slab thickness.

4 in5 in6 inSame area · different specified thickness
Illustration for explanation. Dimensions, quantities and layouts are examples.

Measured concrete volume, in cubic yards

Rectangular slabs. No allowance, order rounding or minimum charge included.
Slab size4 in thick5 in thick6 in thickCustomize
8 × 8 ft0.790.9881.185Use size →
10 × 10 ft1.2351.5431.852Use size →
10 × 12 ft1.4811.8522.222Use size →
12 × 12 ft1.7782.2222.667Use size →
12 × 16 ft2.372.9633.556Use size →
16 × 20 ft3.9514.9385.926Use size →
20 × 20 ft4.9386.1737.407Use size →
20 × 24 ft5.9267.4078.889Use size →
24 × 24 ft7.1118.88910.667Use size →
24 × 30 ft8.88911.11113.333Use size →
30 × 30 ft11.11113.88916.667Use size →

Turn a table value into an order

For a 20 × 20 ft slab at 4 in, the table gives 4.938 yd³ before extra material. A selected 10% allowance makes the requirement 5.432 yd³. If your supplier sells quarter-yard increments, that rounds up to 5.50 yd³. Confirm any minimum charged volume separately.

Understand allowances or add your supplier rate in the slab cost calculator. The numbers shown are rounded for reading; calculators retain precision internally.

References