🏗️ Cement, sand & aggregate calculator for concrete
Planning a slab, footing, column or floor? Enter the size and grade to estimate cement bags, sand and coarse aggregate (in m³ and brass) including wastage, then send the quantities straight to verified suppliers as a quote request.
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How many bags of cement are needed per cubic metre of concrete?
Roughly 6.3 bags (50 kg) for M15, 8 bags for M20 and 11 bags for M25 in a nominal mix, before wastage. This calculator works it out for your volume.
What is the M20 concrete mix ratio?
M20 is 1 part cement : 1.5 parts sand : 3 parts aggregate by volume. M15 is 1:2:4 and M25 is 1:1:2.
Should I use RMC or site mix?
For M30 and above, large pours or tight quality control, ready-mix concrete (RMC) is usually better. For small jobs, a nominal site mix is common. You can request quotes for either from the results panel.