Bricks per square metre and bricks per square foot describe the same wall in different units, and the conversion between them is a single division: one square metre equals 10.7639 square feet, so divide the per-square-metre figure by 10.7639 to get the per-square-foot figure. What changes the count is not the unit but the brick: its face size and the mortar joint. This guide works every standard brick size in both units, shows how the joint moves the count, and gives the tables to count any wall without a calculator, and to check the calculator when one is used.

The conversion: square metres and square feet

One metre is 3.28084 feet, so one square metre is 3.28084 squared, which is 10.7639 square feet. A count per square metre is therefore larger than the count per square foot by that factor, because a square metre is a larger area and holds more bricks. To convert a per-square-metre figure to per square foot, divide by 10.7639. To convert a per-square-foot figure to per square metre, multiply by 10.7639. The UK standard figure, 59.26 per square metre, becomes 5.51 per square foot. The US modular figure, 73.16 per square metre, becomes 6.80 per square foot. The Indian standard figure, 50.0 per square metre, becomes 4.65 per square foot. Rounding to two decimal places is enough for ordering: the waste allowance dwarfs the rounding, and the joint and brick variation dwarf both.

The conversion is exact for area, but the counts derived from it are only as good as the face dimensions they came from. A per-square-foot figure quoted without its brick size and joint is meaningless, because two bricks of different faces give different counts in either unit, and the conversion cannot repair a missing specification. When a supplier quotes bricks per square foot, ask for the brick’s actual dimensions and the joint assumed; when a guide quotes bricks per square metre, check the same. The figures in this guide all assume a 10 mm joint, about 3/8 inch, which is the standard joint for residential brickwork in both systems, and the joint section below shows how the figures move when the joint changes. A count that cannot state its joint is a count that cannot be checked.

Wall area converts the same way. A wall 10 metres by 3 metres is 30 square metres, which is 322.9 square feet, and at 59.26 bricks per square metre it needs 1,778 bricks before waste, while at 5.51 bricks per square foot it needs 322.9 times 5.51, which is 1,779 bricks, the one-brick difference being rounding. A wall 20 feet by 8 feet is 160 square feet, which is 14.86 square metres, and at 73.16 bricks per square metre it needs 1,088 bricks, the same as 160 times 6.80. Work in whichever unit the drawing uses, convert once for checking, and expect the two routes to agree within a few bricks. A disagreement larger than the waste allowance means one route used a different brick, a different joint, or a different wall area, and the difference should be found before ordering.

The face formula, in both unit systems

Each brick in a wall occupies its face plus one mortar joint on the length side and one on the height side. In metric units, the face area in square metres is the length plus the joint, in metres, times the height plus the joint, in metres, and bricks per square metre are one divided by that face area. For the UK brick: length 0.215 metres plus joint 0.010 metres is 0.225, height 0.065 plus 0.010 is 0.075, face area is 0.016875 square metres, and one divided by 0.016875 is 59.26. In imperial units, the face area in square inches is the length plus the joint, in inches, times the height plus the joint, in inches, and bricks per square foot are 144, the number of square inches in a square foot, divided by that face area. For the US modular brick at its nominal size, 8 inches by 2-2/3 inches including a 3/8-inch joint, the face is 21.33 square inches and 144 divided by 21.33 is 6.75 bricks per square foot, close to the hub figure of 6.80 derived from the metric dimensions, the small difference reflecting the metric and imperial standard sizes not being identical.

The depth of the brick, its width, does not enter the face count for a single skin. It enters the wall thickness, the mortar volume, and the skins multiplier, but not the number of bricks covering a square metre of face. That is why a thick brick and a thin brick of the same face size need the same count for a single skin, and why changing the brick’s height or length changes the count while changing its depth does not. The formula also assumes stretcher bond, bricks laid length along the wall, which is the normal facing bond. Header bond, bricks laid width along the wall, uses the brick’s depth as its face length, giving a different count, and English and Flemish bonds mix stretchers and headers, so their counts fall between the stretcher and header figures. For ordering, the stretcher count plus waste is the standard estimate for facing work, and patterned bonds should be taken off from the pattern itself.

Three quantities complete the count once the per-area figure is known: wall area, skins, and waste. Wall area is length times height minus openings, in the same unit system as the per-area figure. Skins multiply the count: 1 for a single skin, 2 for a double skin. Waste multiplies it again: 1.10 for 10 percent. The order quantity is wall area times per-area figure times skins times one plus waste, rounded up. The formula is linear in every input, so an error in any input propagates proportionally: a 10 percent error in wall area gives a 10 percent error in bricks, a wrong skins choice gives a factor-of-two error, and a wrong joint gives a few percent. The skins choice is the error to guard against most, because it is the largest and the easiest to make from ambiguous language, as the companion guide explains.

Standard sizes in both units

The three standard bricks in the hub’s table cover the markets this site’s readers build in. The UK standard brick, 215 mm long, 102.5 mm deep, 65 mm high, with a 10 mm joint, gives a face of 225 by 75 mm, 59.3 bricks per square metre, 5.51 per square foot. The US modular brick, 194 mm long, 92 mm deep, 57 mm high, with a 10 mm joint, gives a face of 204 by 67 mm, 73.2 per square metre, 6.80 per square foot. The Indian standard brick, 190 mm long, 90 mm deep, 90 mm high, with a 10 mm joint, gives a face of 200 by 100 mm, 50.0 per square metre, 4.65 per square foot. The Indian brick is notably taller, 90 mm against 65 mm, which is why it needs fewer bricks per area despite being shorter: height matters as much as length in the face, and a tall brick covers the wall faster. The three figures should be memorised as a set, with their joints, because they are the check figures for any brick count in their markets.

The per-10-square-metre and per-100-square-foot columns are the estimating columns: a 100-square-foot wall in US modular bricks needs about 680 bricks before waste, and a 10-square-metre wall in UK bricks needs about 593. Estimating in round areas keeps the arithmetic mental and the error visible: if a 200-square-foot wall is quoted at 2,000 bricks in US modular, the quote is nearly 50 percent high, because 200 times 6.80 is 1,360, and the discrepancy should be questioned before it is paid for. Real bricks vary by a few millimetres by manufacturer, and metric and imperial standard sizes are not identical, so a supplier’s bricks should be measured and the face recomputed if they differ from the standards above by more than a millimetre or two. The formula survives any brick; the table figures survive only the bricks they describe.

How the joint width moves the count

The joint enters both face dimensions, so its effect is larger than a single-dimension intuition suggests. For the UK brick, a 10 mm joint gives 59.26 per square metre. A 12 mm joint gives a face of 227 by 77 mm, 0.017479 square metres, and 57.21 per square metre, about 3.5 percent fewer bricks and correspondingly more mortar. An 8 mm joint gives a face of 223 by 73 mm, 0.016279 square metres, and 61.43 per square metre, about 3.6 percent more bricks. A 3/8-inch joint, 9.5 mm, gives a face of 224.5 by 74.5 mm and about 59.8 per square metre, between the 8 and 10 mm figures, as expected. The joint is a design choice as well as a tolerance: wider joints suit handmade bricks with size variation, narrower joints suit precise machine-made bricks, and the joint width should be agreed with the bricklayer before the count is finalised, not adjusted after the bricks arrive.

In imperial units the same effect appears as the difference between the nominal and actual sizes. A US modular brick’s actual size is 7-5/8 inches by 2-1/4 inches, and with a 3/8-inch joint its nominal size is 8 inches by 2-2/3 inches, giving 6.75 bricks per square foot by the nominal face. With a 1/2-inch joint, the nominal face becomes 8-1/8 by 2-3/4 inches, 22.34 square inches, giving 6.45 per square foot. The nominal size system exists precisely to make this arithmetic easy: nominal dimensions include one joint, so coursing and counting can be done in round numbers, three courses to 8 inches for modular brick, and the per-area figure follows directly. When a brick is described by its nominal size, the joint is already included, and adding a joint again double-counts it. Check whether any quoted size is actual or nominal before using it in the face formula.

Worked walls: metric and imperial side by side

Wall one, metric: 5 metres by 2.4 metres, UK bricks, 10 mm joint, single skin, one door of 0.9 by 2.1 metres, 10 percent waste. Gross area is 12 square metres, the door is 1.89 square metres, net area is 10.11 square metres. At 59.26 per square metre, the net count is 599.1 bricks, and with waste it is 659.0, rounded up to 660 bricks. Wall two, the same wall in feet: 16.4 feet by 7.87 feet, 129 square feet gross, door 6.2 square feet, net 122.8 square feet, at 5.51 per square foot the net count is 677 bricks, which does not match, and the mismatch is instructive: 5 metres is 16.40 feet and 2.4 metres is 7.87 feet, but the door 0.9 by 2.1 metres is 2.95 by 6.89 feet, 20.3 square feet, not 6.2, so the imperial deduction was wrong, and correcting it gives 108.7 square feet net, 599 bricks, matching the metric route. Unit conversion errors hide in the openings, where two dimensions must both be converted, and the cross-check catches them.

Wall three, imperial: 30 feet by 8 feet, US modular bricks, 3/8-inch joint, single wythe, 30 square feet of openings, 10 percent waste. Gross area is 240 square feet, net area is 210 square feet, at 6.80 per square foot the net count is 1,428 bricks, and with waste 1,570.8, rounded up to 1,571 bricks. In metric, the wall is 9.144 by 2.438 metres, 22.30 square metres gross, openings 2.79 square metres, net 19.51 square metres, at 73.16 per square metre the net count is 1,427 bricks, matching within rounding. Wall four, double skin: the same wall double-wythe needs 2,856 bricks before waste and 3,142 with waste. The four walls together show the method’s consistency: the unit system, the brick standard, and the skins choice are the only inputs, and the same wall counted three ways gives the same answer when the inputs are right.

Other sizes: queen, utility, Norman, and Roman

American manufacturers make a range of sizes beyond modular, each with its own per-area figure at the standard 3/8-inch joint, published in size charts such as Glen-Gery’s brick dimensions guide. Queen bricks, 7-5/8 inches long and 2-3/4 inches high, need about 5.76 bricks per square foot, or 62.0 per square metre. Norman bricks, 11-5/8 inches long and 2-1/4 inches high, need about 4.60 per square foot, or 49.5 per square metre. Utility bricks, 11-5/8 inches long and 3-5/8 inches high, need about 3.00 per square foot, or 32.3 per square metre. Roman bricks, 11-5/8 inches long and 1-5/8 inches high, need about 6.00 per square foot, or 64.6 per square metre. Larger faces need fewer bricks, taller bricks need fewer courses, and the per-area figure falls as either dimension grows. The figures assume the standard joint; a different joint moves them by the same face arithmetic as the standard sizes.

Choosing among sizes is a visual and structural decision, not a counting optimisation. Norman and utility bricks give a long, horizontal emphasis with fewer joints, suited to large walls and modern elevations. Roman bricks give a thin, linear coursing with many joints, suited to detailed facades. Queen bricks sit between modular and Norman, a common facing size. The count difference is real money: a wall in utility bricks needs less than half the bricks of the same wall in modular, but the bricks themselves cost more each, the mortar per brick is higher, and the laying rate differs, so the wall cost does not halve. Price the wall, not the count, and use the per-area figures to check the supplier’s quantity, not to choose the brick. Availability also matters: not every size is stocked at every plant, and a size that must be specially made costs more and takes longer, whatever its per-area figure.

Using the tables, and their limits

The tables in this guide are planning tables: they assume the stated brick size, the stated joint, stretcher bond, and no deduction or waste. To order, apply the three multipliers: deduct openings from the area first, multiply by skins, then multiply by one plus waste, and round up to the supplier’s pack size. Do not apply waste to the gross area and then deduct openings, which double-counts the opening saving, and do not apply the skins multiplier to a cavity wall’s brick skin, which is single-skin. For patterned bonds, corbelling, and decorative coursing, the tables understate the count, because headers, cut bricks, and pattern repeats add bricks that the stretcher face does not show; allow the higher waste figure, 15 percent or more, and take off the pattern separately for large areas. For reclaimed bricks, measure a sample of the actual bricks, since their sizes vary more than new bricks, and compute the face from the measured average, with the joint the bricklayer will hold for that variation.

The tables also assume the wall is flat and rectangular. Curved walls need more bricks for the same face area, because the outer face of a curve is longer than the inner face and the joints open on the curve; the excess depends on the radius and is best taken off from the curve’s geometry or the bricklayer’s experience, with waste at the higher end. Battered walls, sloping walls, and walls with recessed panels each need sectional counting. The tables are the starting point for all of these, not the answer to any of them, and the calculator’s sectional approach, one rectangle at a time, is the right tool for complex walls. When in doubt, count the complex wall in sections, add the sections, and keep the waste allowance for the whole wall, not per section.

Checking a supplier count

A supplier’s count can be checked in under a minute. Ask for the brick size, the joint, the wall area, the skins, and the waste, and recompute the face and the total from those five inputs. If any input is missing, the count cannot be checked, and the missing input should be supplied before the order is placed. If the supplier’s count is higher than the recomputed figure, the difference is usually waste, pack rounding, or a different brick size; if it is lower, the difference is usually a missed skin, an undeducted opening counted the wrong way, or a joint wider than stated. A difference within the waste allowance, up to 10 percent, is normal and reflects different allowances, not an error. A difference of 50 or 100 percent is a skins error, a unit error, or a different wall, and it should be resolved in writing before money changes hands. The cheapest brick is the one that arrives in the right quantity, from the right batch, on the day the bricklayer needs it.

Frequently asked questions

How many bricks per square metre?

UK standard bricks need 59.3 per square metre with a 10 mm joint, US modular bricks 73.2, and Indian standard bricks 50.0. The figures are before waste and for a single skin.

How many bricks per square foot?

UK standard bricks need about 5.51 per square foot, US modular about 6.80, and Indian standard about 4.65, each with a standard joint. Divide the per-square-metre figure by 10.7639 to convert.

How do you convert bricks per square metre to per square foot?

Divide by 10.7639, the number of square feet in a square metre. Multiply by 10.7639 to go the other way. The conversion changes the unit, not the wall, so both routes must give the same total within rounding.

Does the mortar joint change the brick count?

Yes. The joint enters both face dimensions, so widening a UK brick joint from 10 mm to 12 mm cuts the count from 59.3 to about 57.2 per square metre, and narrowing it to 8 mm raises the count to about 61.4.

How many bricks are in 100 square feet of wall?

About 551 UK standard bricks, 680 US modular bricks, or 465 Indian standard bricks, before waste and for a single skin. Add waste and multiply by skins for the order quantity.

Why do different guides give different bricks per square foot?

Because they assume different brick sizes or joints, or quote nominal rather than actual sizes. A count without its brick size and joint cannot be compared with another count. Recompute from the face formula to reconcile them.