Concrete Screed Calculator

Volume = floor area × screed thickness. A 1:2:4 (cement:sand:gravel) mix by weight is typical for a standard floor screed.

3-5 cm (1.2-2 in) is typical for a bonded screed over a slab; thicker unbonded or floating screeds may need 6-10 cm (2.4-4 in).

Standard bags are 50 kg (about 110 lb, though US bags are often sold as 94 lb). The calculator uses 50 kg bags to match the mix-ratio math.

Yes — about 5% shrinkage is typical, which is why the calculator adds a small buffer to the raw volume before working out material quantities.