Concrete calculator for cubic yards and US bag sizes
Measure a slab, footing, column, set of steps or heaped pile in feet or meters. The calculator converts the volume to cubic yards for a ready-mix order and estimates common 80 lb pre-mix bags.
How to use it
Measure once. Order with context.
- 01Choose the shape that best matches the pour.
- 02Select feet or meters and enter the actual dimensions.
- 03Choose ready-mix, pre-mix bags or an indicative site mix.
- 04Review both the measured volume and the result with a 10% allowance.
- 05Confirm the order quantity, mix design, strength, access and minimum load with the supplier.
Estimator, not a mix specification
The result is a volume estimate. It does not choose concrete strength, reinforcement, slab thickness, footing design, air entrainment or exposure class. Follow the project documents, the code adopted by the local authority, product data and the appropriate licensed professional.
Useful conversion
One cubic yard is 27 cubic feet.
The calculator handles that conversion for you, including curved columns and stepped shapes. If a supplier quotes a different bag yield from the common 80 lb assumption shown here, use the yield printed on that exact product.
- 1 yd³ = 27 ft³
- 1 yd³ ≈ 0.765 m³
- 80 lb bag yield varies by product