Calculate the number of cement bags, and the volume of sand and aggregate, needed for a given volume of concrete based on your mix ratio.
How to Use the Cement Calculator
Enter the "Wet Concrete Volume (m³)" you need to cast - use the Concrete Calculator if you only know the slab/element dimensions.
Enter your "Mix Ratio" for Cement, Sand, and Aggregate (e.g. 1:1.5:3 for M20 grade concrete).
Click "Calculate" to see the number of cement bags and the volume of sand and aggregate required.
Frequently Asked Questions
Dry materials (cement, sand, aggregate) have voids between particles that get filled with water and settle when mixed into wet concrete. A standard multiplying factor of 1.54 is used to convert wet (cast) volume into the dry volume of materials needed.
Common nominal mixes include 1:1.5:3 (M20, for slabs/beams/columns), 1:2:4 (M15, for foundations), and 1:4:8 (M7.5, for leveling/PCC). Check your structural drawing or consult an engineer for the correct grade for your application.
Cement density is taken as 1,440 kg/m³, and each standard cement bag weighs 50 kg. The number of bags is rounded up, since you can't purchase a fraction of a bag.
Yes, it's completely free and requires no sign-up.