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Brick Calculator

Construction

Units

Sets result units, the units for new walls, and bag and tie defaults you haven't changed. It never changes the brick count.

Brick

Actual size 7-5/8 × 2-1/4 × 3-5/8 in (L × H × D) · standard joint 3/8 in

Used for both bed (horizontal) and head (vertical) joints.

Wall thickness

Brick veneer, garden walls and the outer leaf of a cavity wall. UK: half-brick wall.

The pattern only changes the drawing, never the count.

Identical walls, e.g. 2 matching garden walls.

Openings

Always deducted, because bricks are laid around them. Door and window sizes are a typical size, measure yours.

whole brick

cut brick

mortar

Not to scale

Net area = L × H − openings

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1 of 30 walls

Brick waste

5% covers breakage and cuts on a plain wall. Use 10% or more for lots of openings, corners or a patterned bond.

Mortar

%
Mortar is dropped, stiffens on the board and fills frogs and cores. Frogged bricks laid frog-up can use much more.

How you'll buy it

ft³
Check the bag. Some list bricks per bag instead.

Results

Enter your wall size to see how many bricks you need.

About This Tool

Brick Calculator – How Many Bricks and How Much Mortar for a Wall

A brick calculator turns wall measurements into a shopping list. Enter each wall, take off the doors and windows, pick a brick size and joint, and this tool counts the bricks to buy with waste. It also works out the mortar, either as bags of pre-mixed mortar or as cement and sand, plus optional wall ties and packs. Every wall is drawn to scale, course by course, so you can see where the cut bricks fall before you start laying.

Nominal vs Actual Brick Size

Brick sizes are often quoted as a nominal size: the brick plus one joint. A US Modular brick is nominally 8 × 2-2/3 × 4 in, so three courses rise exactly 8 in. The actual size is smaller: 7-5/8 × 2-1/4 × 3-5/8 in, laid with 3/8 in joints. A UK brick is 215 × 65 × 102.5 mm, which becomes 225 × 75 mm with its 10 mm joints. The calculator always works from the actual size and adds the joint itself, so custom bricks and non-standard joints are handled the same way.

The Unit-Cell Method

Each brick, together with half of the mortar around it, covers a rectangle of wall called its unit cell: (L + j) × (H + j). Divide the wall area by that cell and you have the number of bricks. For a US Modular brick the cell is 8 × 2-5/8 in = 21 in², so a square foot holds 144 ÷ 21 = 6.86 bricks. A UK brick gives 1 ÷ (0.225 × 0.075) = 59.26 bricks per m², which builders round to 60. The total for the job is the net area of every wall added together, times the bricks per unit area, times the number of wythes, and it is rounded up once, at the end.

Wythes and Bond Patterns

A wythe is one brick-thick layer. Veneer, garden walls and the outer leaf of a cavity wall are single wythe, known in the UK as a half-brick wall. Solid load-bearing and free-standing walls are often double wythe, a one-brick or 215 mm wall, and take twice as many bricks. The bond pattern changes how the wall looks, not how many bricks it needs. English and Flemish bonds swap pairs of stretchers for headers that span both wythes. When the brick length equals two depths plus a joint, as it does for US Modular and UK bricks, the count comes out exactly the same.

Mortar Volume and Mix Ratios

The mortar behind each brick is the unit cell's volume minus the brick's own volume: (L + j)(H + j)D − L·H·D. For solid US Modular bricks that is about 8.1 ft³ per 1,000 bricks, and double-wythe walls add a vertical collar joint. Mortar waste is much higher than brick waste, so 20% is a sensible default. For site-mixed mortar, the wet volume is multiplied by a dry volume factor of about 1.33 and split by the mix ratio. A 1:5 mix is one part cement to five parts sand.

Which mix ratio?
Use 1:3 to 1:4 for strong or below-ground work, and 1:5 to 1:6 for general brickwork above ground. In the US, bagged Type N or Type S mortar mix is the usual choice instead.

Planning Courses to a Height

Each course rises one brick height plus one bed joint. Dividing the wall height by that course gauge tells you how many courses fit. An 8 ft wall of US Modular brick is 36.6 courses. You can either build 37 full courses (8 ft 1-1/8 in), close the joints up slightly, or cut the top course. Planning this before you start keeps courses lined up with window sills and door heads.

How Much Waste to Allow

About 5% covers breakage and cuts on a plain wall. Use 10% or more when a wall has many openings, corners or a patterned bond, where more bricks are cut. Buying from the same batch matters too: bricks from different production runs can differ in colour, so a few spare bricks are cheaper than a mismatched patch later.

Check your bricks and bags
Queen, King and many regional bricks vary between makers, and mortar bag yields vary by product. Measure a brick and read the bag before you order.

Frequently Asked Questions

Is the Brick Calculator free?

Yes, Brick Calculator is totally free :)

Can I use the Brick Calculator offline?

Yes, you can install the webapp as PWA.

Is it safe to use Brick Calculator?

Yes, any data related to Brick Calculator only stored in your browser (if storage required). You can simply clear browser cache to clear all the stored data. We do not store any data on server.

How many bricks per square foot or square metre?

Divide the area by the face one brick and its joints cover, (L + j) × (H + j). A US Modular brick with 3/8 in joints covers 8 × 2-5/8 in = 21 in², so 144 ÷ 21 = 6.86 bricks per ft². A 20 × 8 ft wall takes 1,097 bricks, or 1,152 with 5% waste. A UK brick (215 × 65 mm, 10 mm joints) covers 225 × 75 mm, which is 59.26 per m², so a 5 × 2 m wall takes 593, or 623 with waste.

How much mortar do I need per 1,000 bricks?

For US Modular bricks with 3/8 in joints, the joints behind 1,000 solid bricks hold about 8.1 ft³ of mortar before waste. That is about 15 80-lb bags of mortar mix once you add 20% waste. UK bricks with 10 mm joints need about 0.3 m³ per 1,000. Cored or frogged bricks use noticeably more.

What's the difference between single and double wythe walls?

A wythe is one brick-thick layer. A single-wythe wall (a half-brick wall in the UK) is used for veneer, garden walls and the outer leaf of a cavity wall. A double-wythe wall (a one-brick or 215 mm wall) is two layers side by side, joined by a mortar collar joint or header bricks. It takes twice the bricks and a little more than twice the mortar.

How much waste should I add?

About 5% for bricks on a plain wall, to cover breakage and cuts. Use 10% or more for walls with many openings, corners or a patterned bond. Mortar waste is much higher, around 20%, because it gets dropped, stiffens on the board and fills frogs and cores.

What mortar mix ratio should I use?

For site-mixed cement and sand mortar, 1:5 or 1:6 (cement : sand by volume) suits general brickwork above ground. Use a stronger 1:3 or 1:4 for below-ground work, retaining walls and exposed copings. In the US, bagged Type N or Type S mortar mix is usually used instead, and the calculator counts those bags.

Why does the joint thickness matter?

Every brick takes up its own size plus one joint in each direction, so thicker joints mean fewer bricks and more mortar. Going from 3/8 in to 1/2 in joints on US Modular bricks cuts the count from 6.86 to 6.44 bricks per ft² but raises the mortar by about a quarter. The joint also sets the course height, which decides how the courses line up with doors, windows and the top of the wall.