All 43 tools
Masonry · units · sand · cement
How many bricks do I need?
The core one. 60 bricks or 10 blocks to the square metre, sand off the unit count, cement and lime off the sand by mix ratio — the same chain the old mortar sheet ran, with the below-DPC and above-DPC mixes it used.
Measure it
Every box has its own unit next to it.
Change the unit beside any box and the number converts. The (i) beside each question says what the box wants and where the figure usually comes from. Anything marked per cent is a percentage of the quantity above it.
Check the rates
Rates and assumptions used
These are the figures the calculator works to. Change any of them and the order list updates — your merchant’s pack sizes and your own waste allowances beat the defaults every time.
Order list
The orange figure is the one you order to. Highlighted rows are the other numbers you order to. The small print under each row is the sum that produced it, so you can check it against your own take-off. Amber rows are warnings, not quantities.
How this one works
- Net area =
length × height − openings - Units =
net area × units per m² × (1 + waste %) - Sand =
units laid × sand per unit— worked off the units actually laid, not the ones in the pack - Cement =
sand ÷ sand parts × cement parts, same for lime
The figures the calculator works to. Every one can be changed in step 2, and your merchant’s pack sizes and your own waste allowances beat these defaults every time.
| Rate | Default | Why |
|---|---|---|
| Bricks per m² | 60 no. | Standard 65 mm brick on a 75 mm gauge, stretcher bond. |
| Sand per brick | 1 kg | The old sheet’s figure. Roughly 10 mm joints. |
| Blocks per m² | 10 no. | 440 × 215 block. |
| Sand per block | 1.8 kg | The old sheet’s figure. |
| Cement / lime bag | 25 kg | |
| Sand bulk bag | 0.85 t | |
| Bricks per pack | 500 no. | Common merchant pack. Some are 400. |
| Blocks per pack | 72 no. | Varies by manufacturer. |
| Wall ties | 2.5 per m² | Standard spacing. More at reveals and movement joints. |
A worked example
With the defaults the page opens on:
- How long is it? 12 metres
- How tall is it? 2.4 metres
- Doors and windows to take off? 3.2 square metres
- Brick or block? Facing brick — 60/m²
- Which bond? (bricks only) Stretcher bond - half-brick wall, one leaf
- Which mortar mix? 3:1 — below DPC
- How much spare for breakages? 5 per cent
Walling
- Gross wall area: 28.8 m² — L × H
- Openings deducted: 3.2 m²
- Net wall area: 25.6 m²
- Units per m²: 60 no. — stretcher bond, one leaf
- Waste allowance: 5 %
- Bricks to order: 1,613 no. — 1,536 laid, plus 5% spare
- Packs (as delivered): 4 packs — at 500 a pack - set the pack size in step 2
Mortar — mix 3:1
- Building sand: 1.54 t — 1,536 bricks × 1 kg each
- Sand bulk bags: 2 bags — 1.5 / 0.85 tonnes a bag
- Cement: 21 bags — sand ÷ 3 = 512 kg, in 25 kg bags
- Hydrated lime: none — use a plasticiser instead
- Wall ties, if cavity: 64 no. — 2.5 to the square metre — see the cavity wall calc
Change any figure above and every line recalculates; the small print under each row is the sum that produced it.
Questions people ask
How many bricks are there in a square metre?
Sixty, for a standard 65 mm brick laid in stretcher bond on a 75 mm gauge, which is the figure this calculator uses. A 440 × 215 mm block is ten to the square metre. Both rates are in the rates panel and you can change them.
How much sand and cement do I need per 1,000 bricks?
This calculator works the sand off the bricks actually laid, at 1 kg of building sand per brick, then the cement off the sand by the mix ratio. At 3:1 that is about 1 tonne of sand and 14 bags of cement per 1,000 bricks; at 5:1:1 it is the same sand, about 8 bags of cement and 8 of lime. Change the mix and the figures follow.
Should I deduct doors and windows?
Yes - add up every opening in the run and put the total in "Doors and windows to take off". The old rule of thumb is not to bother deducting anything under about half a square metre, because the cutting round it uses what the opening saved.
Why is the pack count different from the brick count?
Merchants sell bricks by the pack, commonly 500 (some 400), so the order is rounded up to whole packs. The brick count is what you lay plus the spare; the pack count is what arrives.
Calculators for the same job
Doing this for a whole job rather than one wall? SiteLedger keeps the valuations, supplier statements, invoices and variations against the project they belong to.
Read before you order. These work out quantities, not structural design — spans, lintels, rebar and foundation depths need an engineer and Building Control sign-off. Waste allowances are defaults, not promises: awkward cuts, long runs and bad weather all eat more than 5%. Where a merchant sells whole packs, the figure is rounded up to whole packs.