Free calculator · India
Concrete Mix Calculator
Enter the slab, footing or column size and pick a grade to get cement bags, sand and aggregate quantities.
How we calculate
Dry volume = wet volume x 1.54. Each material = dry volume x its part / sum of parts (M15 1:2:4, M20 1:1.5:3, M25 1:1:2). Cement bags = cement volume x 1440 kg/m³ / 50 kg. Sand 1600 kg/m³, aggregate 1550 kg/m³. Wastage is added to the wet volume.
Frequently asked questions
Which grade is used for a house slab?
M20 is common for residential slabs and beams. Your structural engineer decides the final grade.
Why multiply by 1.54?
Wet concrete shrinks when materials mix and settle, so dry material volume is about 54% higher.
How many bags of cement per m³ of M20?
About 8 bags of 50 kg for M20 before wastage.
Is wastage included?
Yes. The default is 5% and you can change it.
Other tools
TMT Steel Weight Calculator Tile Calculator Paint Calculator Construction cost calculator