Brick Mortar Calculator
Find how much mortar you need for your bricks, in litres, bags of mortar mix, or sand and cement.
Measure your job
Your answer
For about 360 bricks (single brick wall), mixed 1 : 5.
Bulk bags are 800 kg. Bags are rounded up.
This answer is a guide. For footings, walls or anything that holds weight, check your local building rules or ask a builder or engineer.
What it costs
UK middle prices from October 2026, with VAT. Cement: £8.39 a 25 kg bag (7 prices from 3 sellers). Bulk bags: £75, building sand £67.35 (3 sellers each). Few prices, so treat them as a rough guide.
Quick answers
- Mortar per brick
- About 0.5–0.6 litres, from Blue Circle, Heidelberg and Cemex figures.
- Bricks per m²
- About 60 in a single brick wall, says Travis Perkins. A double brick wall has 120.
- 1,000 bricks
- About 0.5–0.6 m³ of mortar. That is 53 bags of 20 kg mortar mix.
- One bag of mortar mix
- Heidelberg's 20 kg bag lays about 19 bricks. Cemex's 25 kg bag lays about 20.
How to work it out
- Count your bricks. Or measure the wall in metres: length × height gives m².
- For a single brick wall, m² × 60 gives the number of bricks.
- Multiply the bricks by 0.6 litres. That is the top maker's mortar per brick.
- For 20 kg bags of mortar mix, divide the bricks by 19. Round up.
- Mixing your own? The calculator gives the building sand and cement.
6 × 1 m = 6 m² × 60 = 360 bricks
360 × 0.6 = 216 litres of mortar
360 ÷ 19 = 18.9 → 19 bags of 20 kg
Mortar for 100, 200, 400, 500 and 1,000 bricks
Find the row nearest your count. The litres show the spread between makers. Bags are whole bags, rounded up.
| Bricks | Mortar (litres) | 20 kg bags | 25 kg bags |
|---|---|---|---|
| 100 | 50–60 | 6 | 5 |
| 200 | 100–120 | 11 | 10 |
| 400 | 200–240 | 22 | 20 |
| 500 | 250–300 | 27 | 25 |
| 1,000 | 500–600 | 53 | 50 |
Single brick wall, 10 mm joints. 20 kg bags: Heidelberg, 19 bricks each. 25 kg bags: Cemex, 20 bricks each.
To mix your own instead, the calculator above gives building sand and cement. Our sand and cement calculator has the full list for 1,000 bricks.
Mortar per brick, by maker
Three UK makers say how many bricks their mortar lays. We turned that into litres per brick.
| Maker | What they say | Litres per brick |
|---|---|---|
| Blue Circle | 1 m³ lays 1,800–2,000 bricks | 0.5–0.56 |
| Heidelberg | 20 kg bag (0.011 m³) lays about 19 | 0.58 |
| Cemex | 25 kg bag (12 litres) lays about 20 | 0.6 |
A double brick wall takes more mortar for each brick. Blue Circle says 1 m³ lays 1,400–1,600 bricks in a double wall. That is about 0.63–0.71 litres a brick.
How many bricks to order
A single brick wall has about 60 bricks per m². Travis Perkins says 1,000 bricks cover about 16 m², with enough spare for 5% waste.
Bricks per bag of mortar mix
- Heidelberg, 20 kg, ready to use: about 19 bricks a bag. So 1,000 bricks take 53 bags. Add about 2.8 litres of water to each.
- Cemex, 25 kg, dry mortar: about 20 bricks a bag, or 50 bags per 1,000. Add 3.5–4 litres of water, and use it within 2 hours.
- On a pallet: In its 2021 guide, Hanson packed its 20 kg M6 mortar 60 bags to a pallet. It marked that bag not on sale.
We have no checked UK price for bags of mortar mix yet, so the calculator prices sand and cement only.
What goes in brick mortar
- Building sand: about 1 kg per brick, since a tonne of mortar lays about 1,000 bricks (BDA, MPA).
- Cement: in 25 kg bags. At 1 : 5, we use the MPA's 150 kg of cement per tonne of sand. Its figure is for lime and sand.
- Mix: Gilmore Building Supplies names 1 : 5 as a common bricklaying mix. That is class M4. Screwfix suggests 1 : 4 for standard walls.
- Lime or plasticiser: the BDA says weaker mixes need one, so they stay workable. Don't use washing-up liquid.
Don't lay bricks when it is 2 °C and falling, says the BDA. For a wall that holds weight, check your local building rules or ask a builder or engineer.
Questions people ask
How much mortar per brick?
About 0.5–0.6 litres for a single brick wall. Blue Circle gives the low end and Cemex the high end.
How much mortar do I need to lay 100 bricks?
About 50–60 litres. That is 6 bags of 20 kg mortar mix.
How much mortar to lay 1,000 bricks?
About 0.5–0.6 m³. In bags, that is about 53 × 20 kg (Heidelberg), or 50 × 25 kg (Cemex).
How do you calculate mortar for a brick wall?
Count the bricks, or take m² × 60. Allow about 0.6 litres a brick. So 300 bricks take about 180 litres.
How many bricks are in 1 m³ of wall?
About 500, with the mortar, says Travis Perkins.
How much mortar for 500 bricks?
About 250–300 litres. That is 27 bags of 20 kg mortar mix (Heidelberg), or 25 bags of 25 kg (Cemex).
How much mortar goes between bricks?
Cemex works out its bag figures for 10 mm joints. Thicker joints use more mortar, so you would need more bags.
What do I need for brick mortar?
Building sand, cement and water. Weaker mixes also need lime or a plasticiser. Or buy bags of mortar mix and just add water.
Where our numbers come from
- Bricks per m² and 1:5 mortar: Travis Perkins brick calculator
- Mortar per brick: Blue Circle Quality Assured Mortar data sheet
- Ready-mixed mortar bags: Heidelberg Sand & Cement Mortar data sheet (20 kg lays about 19 bricks)
- Mortar per bag: Cemex (25 kg lays 12 blocks or 20 bricks)
- Hanson packed products guide (2021): bags per pallet
- Sand per 1,000 bricks: Brick Development Association, Mortar for Brickwork
- Bricks per tonne: Mineral Products Association Mortar Data Sheet 01
- Mortar and render mixes, cement and mortar per tonne of sand: MPA sheet 04
- Mortar mixes: Heidelberg Multicem data sheet
- Mixes, shovels per bag, cement per bulk bag: Gilmore Building Supplies guide
- Mortar mix for walls: Screwfix guide to making mortar (4 to 1)
- Mix ratios and 25 kg bags: Heidelberg General Purpose cement data sheet
- Ballast weight: Wickes ballast bulk bag (800 kg covers 9.7 m² at 50 mm)
- Cement price: the middle of 7 prices from 3 UK sellers (25 kg, Oct 2026)
- Bulk bag prices: the middle price from 3 UK sellers each (Wickes, Tippers, Lawsons; Oct 2026)
Made by BuildersCount. Last checked 4 Oct 2026.
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