How to use the concrete calculator
- Choose feet and inches, or metres and centimetres.
- Enter the length, width and thickness.
- Read the volume and bag counts.
Bags and extra
An 80 lb bag of pre-mixed concrete makes about 0.6 ft³ and a 60 lb bag about 0.45 ft³. The bag counts include about 10% extra for spills and uneven ground. For large slabs, ready-mixed concrete by the yard or cubic metre is usually cheaper.
Examples
1.23 yd³ · 62 bags of 80 lb
0.6 m³