Sand and cement calculator
Work out how much sand and cement you need for mortar, screed, render or bedding. Enter the area, the depth and your mix ratio and this calculator gives you the sand in tonnes and the cement in bags.
Sand and cement calculator
Enter your measurements in metres. Everything updates as you type, and nothing is sent anywhere.
The ratio is the sand parts to one part cement, so 4 means a 4:1 mix. Quantities assume about 35% extra dry material over the finished volume, with cement at roughly 1.44 tonnes per cubic metre and sand at 1.6 tonnes. Common ratios: 3:1 for a strong screed or pointing, 4:1 for general screed and bricklaying mortar, 5:1 or 6:1 for render and internal work.
Common questions
How much sand and cement do I need for screed?
For a floor screed, work out the area times the thickness for the volume, then split it by your mix ratio. A 4:1 screed at 50mm over 20 square metres needs roughly 1.7 tonnes of sand and about a dozen 25kg bags of cement, plus a bit extra. The calculator works it out for your exact size and ratio.
What ratio of sand to cement for mortar?
About 4:1 sand to cement for general bricklaying, 3:1 for exposed or below-ground work and repointing, and 5:1 to 6:1 with plasticiser for softer internal blockwork. A stronger mix is not always better, since it can be too hard for softer bricks.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing. These quantities are a guide to help you order. Always round up and check with your supplier before buying.