Loose material compacts down — over-order a little so you don't run short.
A traditional sand-and-cement floor screed levels off a base before flooring goes down, usually laid 50–75mm thick at a 1:4 cement-to-sand ratio. Enter the floor area and screed thickness to size the sharp sand and cement.
How to use this calculator
- Measure the floor area in square metres.
- Set the screed thickness — typically 50–75mm for a bonded or unbonded screed.
- Keep a wastage allowance for mixing losses.
- Get delivered quotes for the sharp sand and cement.
How we work this out
We take your area and finished depth, work out the volume in cubic metres, then convert to weight using a loose delivered density of 2 tonnes per cubic metre for Sharp / screeding sand — the figure used across the UK trade. The compaction and wastage allowance is added on top so you don’t run short. Bulk-bag counts assume a standard 850 kg dumpy bag.
Delivered densities and coverage vary with grade, moisture and how hard the material is compacted, so these figures are a working estimate to size your order — always confirm the exact quantity and price with your supplier before buying. Our team reviews the density figures and guidance periodically; this page was last reviewed on 12 July 2026.
Frequently asked
How thick should a floor screed be?
A bonded screed can be 25–40mm; unbonded 50mm+; a floating screed over insulation 65–75mm.
What sand is used for screed?
Sharp (screeding) sand at roughly a 1:4 cement-to-sand ratio for a standard levelling screed.