Brick Calculator UK: How Many Bricks and How Much Mortar Do You Need?

Enter your wall length and height, take off any doors and windows, and this brick calculator works out how many standard UK bricks you need, then estimates the mortar in sand and cement. A standard brick face plus a 10mm joint gives 60 bricks per square metre for a single-skin wall and 120 for a one-brick (double-skin) wall.

How it is calculated

A standard UK brick has a face of 215 x 65mm, and the full brick is 215 x 102.5 x 65mm. Once you add a standard 10mm mortar joint around it, each brick takes up a coordinating area of 225 x 75mm on the face of the wall. That works out to:

• 60 bricks per square metre for a single-skin (half-brick) wall, the usual garden wall or skin of a cavity wall
• 120 bricks per square metre for a one-brick (double-skin) solid wall, which is two leaves thick

The brick count is simply:

bricks = (wall area − openings) × 60 or 120, then × 1.07 for 7% wastage

The 7% wastage covers cuts at reveals and corners, breakages on site, and the odd brick that does not make the grade. For the mortar, the tool uses the standard UK rate of 0.022 m³ of mortar per m² of single-skin brickwork, doubled for a one-brick wall. That volume is split into sand and cement: soft building sand weighs about 1.6 tonnes per cubic metre, and a 4:1 mix needs about 12.5 bags of 25kg cement per cubic metre of mortar (10 bags for 5:1, about 8.3 for 6:1). Cement is rounded up to whole bags.

Worked example

Say you are building a single-skin wall 10m long and 2.4m high, with no openings, at a 4:1 mix.

• Area: 10m × 2.4m = 24 m²
• Bricks: 24 × 60 = 1440, × 1.07 = 1,541 bricks
• Mortar: 24 × 0.022 = 0.528 m³, × 1.07 = 0.56 m³
• Sand: 0.56 × 1.6 = 0.90 t (about 900kg)
• Cement: 0.56 × 12.5 = 7.1, rounded up to 8 bags of 25kg

So roughly 1,541 bricks, one bulk bag of sand and eight bags of cement cover that wall, with a little spare.

Frequently asked questions

How does this brick calculator UK work?

This brick calculator uses standard UK figures: a 215 x 65mm brick face with a 10mm mortar joint, giving 60 bricks per square metre for a single-skin wall and 120 for a one-brick double-skin wall. Enter the wall length and height, or the total area, take off any openings, and it returns the brick count with 7% wastage plus a brick mortar estimate in sand and cement.

How many bricks are there in a square metre?

There are 60 standard bricks in a square metre of single-skin (half-brick) wall, allowing for a 10mm mortar joint. A one-brick solid wall is two leaves thick, so it takes 120 bricks per square metre. Those are the figures almost every UK bricks calculator and merchant uses, so they make a reliable starting point for ordering.

How many bricks do I need for my wall?

Multiply the net wall area in square metres by 60 for a single skin or 120 for a double skin, then add 7% for wastage. For example, a 10m by 2.4m single-skin wall is 24 m², which is 1,440 bricks before wastage and about 1,541 after. Always subtract the area of any doors, windows or gates first so you are not paying for bricks you will never lay.

Can I use this as a brick mortar calculator?

Yes. As well as the brick count, the tool gives a brick mortar estimate. It allows about 0.022 m³ of mortar per square metre of single-skin brickwork, doubled for a one-brick wall, then splits that into soft building sand in tonnes and 25kg cement bags for your chosen mix. That makes it a combined bricks calculator and brick mortar calculator in one.

How much sand and cement do I need per 1000 bricks?

For single-skin work, 1000 bricks cover about 16.7 m², which needs roughly 0.37 m³ of mortar. With 7% wastage that is about 0.39 m³, or roughly 0.63 tonnes of sand and five 25kg bags of cement at a 4:1 mix. A common rule of thumb is about one tonne of sand and six to seven bags of cement per 1000 bricks, which leaves a little spare.

What size is a standard UK brick?

A standard UK brick is 215mm long, 102.5mm wide and 65mm high. With a 10mm mortar joint added, the coordinating size is 225 x 75mm on the face, which is why 60 bricks fill a square metre of single-skin wall. Imperial and handmade bricks vary, so if you are using a non-standard brick, check its coordinating size and adjust the count.

How much wastage should I allow on bricks?

Allow about 5% to 10% wastage on bricks for cuts at corners and reveals, breakages on site, and rejects. This calculator adds 7% as a sensible middle figure. Order in full packs because part packs are awkward to buy later, keep some spares back for repairs, and add a little more for complex shapes with lots of cutting.

Should I confirm these brick quantities before ordering?

Treat the result as a planning estimate. Real brick and mortar use varies with bond, joint thickness, brick type and the bricklayer, and bricks are often sold by the pack. For anything structural or load-bearing, confirm quantities and the specified mortar mix with your supplier or a qualified engineer before you order and build.