Mortar Calculator
Work out the sand and cement needed for a volume of mortar.
Sand required
0.8tonnes
- Cement
- 7 × 25 kg bags
- Cement weight
- 160 kg
Based on a single 4:1 sand to cement mix, about 320 kg of cement per cubic metre.
v1.0 · Reviewed September 2026
How this is worked out
The mortar volume you enter is converted to sand at 1.6 tonnes per cubic metre and cement at 320 kg per cubic metre, with the cement also shown as whole 25 kg bags.
Worked example
- Mortar volume 0.5 m³
0.5 × 1.6 = 0.8 tonnes sand; 0.5 × 320 = 160 kg cement, so 7 bags
0.8 tonnes of sand and 160 kg of cement
Assumptions and limits
- Sand is measured loose at 1.6 tonnes per cubic metre and cement at 320 kg per cubic metre of mixed mortar. Because the cement fills voids between the sand grains, these figures are not a 4:1 ratio by weight.
- Lime, plasticiser and waste are not included.