How Many Bricks Are in 1 Cubic Meter With Mortar?

About 500 bricks make up one cubic metre of brickwork built from the 190 × 90 × 90 mm standard brick with 10 mm mortar joints. That is the number nearly every estimating table gives, and it comes from treating each brick as filling a nominal 200 × 100 × 100 mm box: 1 ÷ 0.002 = 500.

Assumptions: 190 × 90 × 90 mm brick, 10 mm bed and head joints, mortar joints filled solid, no wastage included.

Count the bricks in an actual wall and you get a little more, because the outer faces of a wall do not carry a mortar joint. A 190 mm one-brick wall holds about 526 bricks per m³, and a 90 mm half-brick wall holds about 556. Both matter, and this guide explains which to use when.

Why there is no single number

The count depends on three things, and every one of them varies by country and by job.

Brick size. A 190 × 90 × 90 mm brick and a 215 × 102.5 × 65 mm brick are different objects. The counts differ by more than 5 percent for the same wall type, and more once wall thickness changes with them.

Joint thickness. The joint adds to both the length and the height of every brick’s footprint, and to the wall thickness on a two-leaf wall. Moving from 6 mm to 15 mm drops the count by about 17 percent.

Wall thickness. A half-brick wall has no joint running through it. A one-brick wall has a collar joint between the two leaves. Same brick, different answer.

Any article that gives one number without naming those three has not answered the question.

Bricks per cubic metre by brick size

Assumptions: running bond, bed and head joints of the thickness shown, joints filled solid, a collar joint of the same thickness between the leaves of a one-brick wall, no wastage. The mortar column is wet mortar in place, expressed as cubic metres per cubic metre of brickwork.

The two count columns are both defensible and they answer slightly different questions, which the next section explains.

Nominal module versus exact wall count

The nominal-module method gives every brick a mortar joint on all three axes:

Bricks per m³ = 1 ÷ [(length + joint) × (height + joint) × (width + joint)]

For 190 × 90 × 90 mm at 10 mm joints that is 1 ÷ (0.2 × 0.1 × 0.1) = 500.

It is simple, it is what estimating tables and textbooks use, and it is conservative on mortar. What it is not is a description of a wall, because the outer face of a wall has no mortar on it. The method effectively spreads half a joint over each of the two wall faces, which is why it returns fewer bricks and more mortar than reality.

The exact wall count works from the face module and the wall thickness:

Bricks per m² of face = 1,000,000 ÷ [(length + joint) × (height + joint)]   (mm)
Wall thickness        = (leaves × brick width) + (leaves − 1) × joint
Bricks per m³         = (bricks per m² × leaves) ÷ wall thickness in metres

For the same brick in a 190 mm one-brick wall: 50 per m² of face, two leaves, 0.19 m thick, so (50 × 2) ÷ 0.19 = 526 bricks per m³.

Which should you use? For ordering bricks, use the exact count and then add breakage on top, because the nominal method under-orders by 5 to 10 percent. For mortar, the nominal method’s higher figure is the safer of the two, and it happens to sit close to a net volume plus a modest waste allowance.

Nominal, specified and actual dimensions

The words matter here, and mixing them is the most common source of a wrong answer.

• Nominal is the brick plus its intended joint. The 200 × 100 × 100 mm figure is nominal.
• Specified is the size the brick is made to and sold as. The 190 × 90 × 90 mm figure is specified.
• Actual is what turns up on the pallet, within the tolerance its standard allows.

Brick Industry Association Technical Note 10 makes the same distinction for US brick, and notes that non-modular sizes such as the US standard brick have no nominal dimensions at all. If you use a nominal dimension for the brick and then add a joint to it, you have counted the joint twice.

Joint thickness changes the count

Joint thickness has a larger effect on the count than most people expect, because it applies to length, height and, in a two-leaf wall, thickness.

Assumptions: 190 × 90 × 90 mm brick, running bond, two leaves with a collar joint of the same thickness, joints filled solid, no wastage.

Going from a 6 mm joint to a 15 mm joint costs you 96 bricks per cubic metre and more than doubles the mortar. Thick joints are not free, and the mortar joint thickness guide covers what the standards allow.

Worked example: a 190 mm wall

A boundary wall 12 m long, 2.5 m high and 0.19 m thick, in 190 × 90 × 90 mm brick with 10 mm joints.

1. Wall volume = 12 × 2.5 × 0.19 = 5.7 m³
2. Face area = 12 × 2.5 = 30 m²
3. Bricks per m² of face = 1,000,000 ÷ (200 × 100) = 50
4. Leaves = 2, so bricks = 30 × 50 × 2 = 3,000 bricks
5. Cross-check: 5.7 m³ × 526 per m³ = 2,998 bricks
6. Solid brick volume = 3,000 × 0.001539 = 4.617 m³
7. Wet mortar = 5.7 − 4.617 = 1.083 m³
8. Add 5 percent breakage to the bricks = 3,150 bricks to order

The nominal-module method would have given 5.7 × 500 = 2,850 bricks, which is 150 short before any breakage allowance at all. That is the practical cost of using the convention for an order.

Worked example: a UK half-brick wall

A single-leaf garden wall, 8 m long by 1.8 m high by 102.5 mm thick, in 215 × 102.5 × 65 mm brick with 10 mm joints.

1. Wall volume = 8 × 1.8 × 0.1025 = 1.476 m³
2. Face area = 14.4 m²
3. Bricks per m² = 1,000,000 ÷ (225 × 75) = 59.3
4. Bricks = 14.4 × 59.3 = 854 bricks
5. Cross-check: 1.476 m³ × 578 per m³ = 853 bricks
6. Wet mortar = 14.4 m² × 0.0176 m³ = 0.253 m³
7. Add 5 percent breakage = 897 bricks to order

Working per square metre of face is faster than working per cubic metre for a single-leaf wall, and it is less error-prone because there is no wall thickness to get wrong. Cubic metres come into their own on thick walls and on bills of quantities that are priced by volume.

From bricks to mortar

The two questions are the same calculation seen from different sides. Once you know the brick count and the wall volume, the mortar is what is left:

Wet mortar = wall volume − (brick count × solid volume of one brick)

That is the whole of the brickwork mortar calculation, which goes on to convert wet mortar into the dry cement and sand you actually buy. The conversion matters: dry material occupies roughly a third more volume than the mortar it produces, so 1.083 m³ of joints in the example above needs about 1.44 m³ of dry material before waste.

If you would rather work from wall area than wall volume, the mortar per m² figures give a single multiplier per wall type.

Breakage is separate from the count

Bricks per cubic metre is a geometry question. How many bricks to buy is a logistics question, and they should not be mixed into one number.

BIA guidance is to add at least 5 percent to a brick quantity for breakage and waste, with more on jobs that involve heavy cutting, many openings, several returns, or a bond pattern that needs half bats and closers. Deliveries also arrive with a share of damaged units, and a wall built from two deliveries of slightly different colour is worse than one built from a single over-order.

Keep the two figures visible separately on your take-off. When someone later asks why the order was 3,150 rather than 3,000, the answer should be on the sheet.

Running your own numbers

The counts above hold for the exact brick sizes and joints listed. For a brick that is not on the list, or a wall that is not a plain rectangle, put your own dimensions into the Mortar Calculator. It takes a custom unit size in millimetres or inches, applies your joint thickness, and returns both the unit count and the mortar volume, so you can see the two sides of the same calculation together.

One last check worth doing on any answer, including your own. Multiply your bricks per cubic metre by the solid volume of one brick. The result should be between about 0.79 and 0.86, meaning brick fills 79 to 86 percent of the wall and mortar fills the rest. Anything outside that range means a dimension or a joint has gone in wrong.