Measure the wall face
Enter the total run of wall and its height, then add each door and window with its own size. For a house, add the length of every wall together and work with an average height, or calculate each elevation separately.
Brick calculator
Brick, block &
mortar calculator
A free online brick calculator that turns wall dimensions and openings into an order-ready count of bricks or concrete blocks, plus mortar bags or cement and sand, wall ties, reinforcement and course heights. US, UK, Australian, Indian and South African unit sizes included.
Enter measurements ↓
Based on your result
What you'll need
Quantities update after every calculation. Order bricks and blocks from one production batch where possible, because colour and size vary between batches.
- Bricks or blocks
Selected unit size, including the waste allowance
- Calculate above
- Jamb closers
Half units cut for the reveals in running bond
- Calculate above
- Mortar
Pre-mixed bags, or cement for a site-mixed batch
- Calculate above
- Sand
Building sand for site-mixed mortar
- Calculate above
- Wall ties
Ties between wythes, or to the backing structure
- Calculate above
- Bed reinforcement
Ladder or mesh reinforcement laid in the bed joints
- Calculate above
- Lintels
One per opening, sized with the bearing at each end
- Calculate above
- Damp-proof course
DPC or flashing along the base of every leaf
- Calculate above
- Weep holes
Above the DPC and over every lintel or cavity tray
- Calculate above
- Movement joints
Vertical joints that let the wall expand and shrink
- Calculate above
- Core fill grout
Grout for filled block cores on retaining walls
- Calculate above
- Cavity trays and insulation
Trays over openings, cavity insulation and sealants
- As required
Foundations, structural reinforcement, lintel sizes, cavity insulation and movement-joint spacing are project-specific and are not included in these quantities.
Masonry guide
How this brick calculator estimates bricks and mortar
Masonry is counted per unit of wall face. The brick calculator adds the mortar joint to the unit length and height to get the module size, divides the net wall area by that module, and multiplies by the number of wythes in the wall.
Mortar follows from the joints rather than a flat rule of thumb: the bed and head joint around every unit, bedded full for solid brick and on the face shells for hollow block, plus the allowance for furrowing, squeeze-out and waste on the board.
Add the joint to the unit
A modular brick with a 3/8 in joint occupies 8 × 2⅔ in, which gives about 6.9 bricks per square foot. A UK brick with a 10 mm joint occupies 225 × 75 mm, or just under 60 bricks per square metre.
Count the leaves of the wall
A single-wythe garden or veneer wall uses one leaf. A full-brick or cavity wall uses two, which doubles the units and adds a collar joint or cavity plus wall ties between the leaves.
Allow for cuts and breakage
Ten percent suits most walls. Increase it where there are many returns, angles, arches or reveals, and where units are handled several times before they reach the wall.
Block calculator for walls, houses and retaining walls
Standard American concrete blocks have a 16 × 8 in nominal face, which works out at 1.125 blocks per square foot, or 112.5 blocks per 100 square feet. UK blocks at 440 × 215 mm give about 10 blocks per square metre. Only the thickness changes between a 4, 6, 8 and 12 in block, so the face count stays the same while the mortar volume and wall weight rise.
For a retaining wall, select the core fill option that matches the design. Filling every second core, every fourth core or grouting solid changes the grout volume dramatically, and the calculator shows that volume separately from the mortar.
Retaining walls also need drainage, a compacted footing and vertical reinforcement sized by an engineer. Use the quantities here for budgeting and ordering, not as a structural design.
Mortar calculator for brick and blockwork
Mortar is quoted two ways. Pre-mixed bags are simplest: an 80 lb bag yields roughly 0.6 cubic feet of mortar, which lays about 30 modular bricks or 12 concrete blocks. Site-mixed mortar is quoted as a cement to sand ratio, commonly 1:4 for general brickwork, 1:5 or 1:6 for internal blockwork.
This mortar calculator works from the joint geometry of the unit you selected, then adds the site allowance masons actually use: solid bricks take a full bed, hollow blocks are face-shell bedded, and a thicker joint or a second wythe raises the volume automatically. Sand and cement are shown as dry, loose volumes: a wet mortar volume needs roughly 30 percent more dry material, which is the standard dry-volume allowance in masonry estimating.
Mix only what can be laid before the mortar starts to stiffen, keep the mix consistent so the joint colour matches across the wall, and protect fresh work from rain, frost and direct sun.
Unit sizes
Bricks per square foot and per m²
Rates below include the standard joint for each format. Change the joint in the form and every rate updates with it.
- Modular brick
- 7⅝ × 2¼ in with a 3/8 in joint: about 6.9 bricks per square foot of wall face.
- UK standard brick
- 215 × 65 mm with a 10 mm joint: 59.3 bricks per square metre, the trade figure of 60, for a single skin.
- Concrete block
- 16 × 8 in nominal face: 1.125 blocks per square foot, whatever the block thickness.
- Australian brick
- 230 × 76 mm with a 10 mm joint: about 48.5 bricks per square metre.
The maths
From wall area to brick count
Each unit occupies its own size plus one mortar joint in both directions. Dividing the net wall area by that module gives the rate per square foot or square metre, and mortar is whatever volume of the wall the units do not fill.
net area = wall length × height − openings
module = (unit length + joint) × (unit height + joint)
units = net area ÷ module × wythes × waste
courses = wall height ÷ (unit height + joint)
mortar = (bed + head joint) × units × site allowance
module = (unit length + joint) × (unit height + joint)
units = net area ÷ module × wythes × waste
courses = wall height ÷ (unit height + joint)
mortar = (bed + head joint) × units × site allowance
- 01
Measure the wall face
Total run of wall by height, then subtract every door and window opening.
- 02
Pick the unit size
US, UK, Australian, Indian and South African formats, plus concrete blocks and custom sizes.
- 03
Set the joint
3/8 in is standard in the US, 10 mm across the UK, Australia, India and South Africa.
- 04
Choose the build-up
One wythe for a veneer or garden wall, two for a full-brick or cavity wall with ties.
- 05
Order whole packs
Units, mortar bags, cement, ties and reinforcement are each rounded up separately.
Before you order
Brick and block questions, answered
About 6.9 modular bricks per square foot of single-wythe wall with a 3/8 in joint, because each brick occupies 8 by 2 5/8 in with its joints. The often-quoted 6.75 comes from nominal 8 by 2 2/3 in coursing. A two-wythe wall needs twice that.
A UK standard brick with a 10 mm joint occupies 225 by 75 mm, so 59.3 bricks per square metre for a single skin, quoted in the trade as 60, and double that for a one-brick wall. Australian bricks give about 48.4 per square metre.
Standard 16 × 8 in blocks give 1.125 blocks per square foot, so a 24 by 8 ft wall without openings needs about 216 blocks before waste.
About 19 cubic feet for 1,000 modular bricks, which is roughly 32 pre-mixed 80 lb bags at a 0.6 cubic foot yield. That is well above the theoretical joint volume because mortar is furrowed, squeezed out and lost in the mixer. Blockwork works out at about three bags per 100 blocks.
1:4 is the general-purpose mix for brickwork, 1:3 where higher strength is specified, and 1:5 or 1:6 for internal blockwork. Follow the specification or engineer for structural work.
Yes, and every opening is entered on its own row with its own width and height, so a wide patio door and a small bathroom window are deducted separately. The total opening area is removed from the wall before the units are counted.
For a paved area, calculate the paving area and divide by the face area of one paver plus the joint. This page is set up for vertical walls, so pavers laid flat need the paver face dimensions entered as a custom unit.
Yes. In running bond each jamb finishes with a half brick on every second course, so a 6 ft 9 in door adds around 30 closers on a single-wythe wall. Each closer is cut from a whole brick, so the calculator counts them and adds the missing half on top of the area figure. Stack bond aligns the joints and needs none.
The calculator uses about one tie per 2.7 square feet for two-wythe and cavity walls, which matches the common 900 × 450 mm spacing. Local codes, wind exposure and cavity width can require more.
One lintel per opening, each as wide as the opening plus the bearing you set at both ends, which is normally 4 to 6 in in the US and 150 mm in the UK. DPC runs the full length of every leaf, and weep holes are counted along the DPC and over each lintel at the spacing you choose, up to the 33 in maximum.
No download is needed: the same page works as a brick calculator app and a block calculator app in the phone browser. Add it to the home screen from the browser menu and it opens with an icon while you are on site, with the 3D wall and every unit size available.
No. It estimates quantities only. Foundations, reinforcement, lintels, retaining-wall design, movement joints and code compliance need a qualified engineer or building professional.
Planning estimate only. Confirm unit sizes, joint thickness, mortar specification, tie spacing, reinforcement and structural requirements with your supplier, engineer or building control before ordering or starting work.