Calculator
Mortar calculator: sand and cement
Allow about 0.55 m³ of mortar per 1,000 bricks; at a 1:4 mix that is about 1 tonne of building sand and 8 to 9 bags of 25 kg cement.
Enter your sizes, see the materials and a diagram, then send the list for a delivered price.
Quantities are estimates using standard UK rules of thumb and are shown with their working. We check them against your job before we price anything.
How the calculation works
- Mortar volume = bricks ÷ 1,000 × 0.55 m³ (for blockwork the block calculator uses 0.0085 m³ per m² of 100 mm wall)
- Dry volume = mortar × 1.33
- Cement share = dry volume ÷ (1 + sand parts); cement at 1,440 kg/m³
- Sand = the rest, at about 1.6 tonnes per m³
Worked example
2,000 bricks at 1:5: mortar 1.1 m³, dry volume 1.46 m³. Cement 0.24 m³ (about 350 kg, so 15 bags rounded up). Sand 1.22 m³ (about 1.95 tonnes).
What to order with it
- Cement: 25 kg bags of general-purpose and rapid-set cement.
- Building & Sharp Sand: Soft building sand, sharp sand and plastering sand.
- Bagged Concrete & Mortar Mixes: Post mix, ready-to-use concrete, mortar and screed in bags.
Quantities are estimates. Pack sizes, bag weights and coverage vary by manufacturer; we confirm them on your quote.
Questions
How many bags of cement for 1,000 bricks?
At a 1:4 mortar mix, about 8 to 9 bags of 25 kg cement and roughly 1 tonne of building sand, allowing for waste.
What is the difference between building sand and sharp sand?
Building (soft) sand is fine and makes smooth mortar for laying bricks. Sharp sand is coarser, drains better and is used in concrete, screeds and paving beds.
Send your list, get a delivered price
Tell us what you need and where it is going. We check the quantities and come back with a delivered price before you commit.