20 bags = 1 tonne
A cement bag is 50 kg, so twenty bags make one tonne. Lorry loads are quoted in tonnes.
How much material do you need?
Enter your measurements and get the bags of cement, tonnes of sand and aggregate for the job — then send the list straight to us.
How much for a concrete pour?
Enter the size of the slab, beam or footing you are casting.
How much for plastering?
Enter the wall area you are plastering.
How much for a wall?
Enter the wall area and how thick the wall is.
Please read this before you order
These are estimates, worked out with the standard site formulas. They do not allow for wastage, spillage, uneven surfaces or openings you have not deducted. Most sites add 5–10% on top. Always confirm the final quantity with your engineer or mason before you place the order.
Rules of thumb worth knowing
1 bag ≈ 0.035 m³
One 50 kg bag of cement takes up about 0.035 cubic metres, or roughly 1.25 cubic feet.
M20 ≈ 8 bags per m³
A cubic metre of M20 concrete takes roughly 8 bags of cement, half a tonne of sand and a tonne of aggregate.
Add 5–10% spare
Every site loses some material to wastage and spillage. Order a little over rather than stopping work halfway.