How many bricks do I need for a wall?

Quick answer

Use net wall area, not gross wall area

First multiply wall length by wall height. Subtract the measured area of doors, windows, or other openings that will not receive brick. Multiply that net wall area by the coverage rate for the brick you are actually estimating, apply the waste allowance, and round the final purchase quantity upward to whole bricks.

For one documented example, BIA Technical Note 10 Table 4 lists 675 Modular bricks per 100 ft² for its running- or stack-bond estimating basis. That is 6.75 bricks per ft² before waste.

The formula

Brick quantity from wall area and coverage

BuildMeasure keeps the exact net quantity unrounded internally. Waste is applied after the net estimate, then the final purchase quantity is rounded upward once so a fractional brick never becomes an understated order.

Worked example

A 20 ft × 8 ft wall with 16 ft² of openings

This is a quantity example only. It uses the BIA Modular coverage rate and a 5% waste/breakage allowance; it does not recommend wall geometry, bond, or structural details.

1. Gross wall area: 20 ft × 8 ft = 160 ft².
2. Net wall area: 160 − 16 = 144 ft².
3. Modular coverage: 144 × 6.75 = 972 net bricks.
4. Allowance: 972 × 1.05 = 1,020.6.
5. Final order: round upward → 1,021 bricks.

The same known-result vector is covered by the Brick Calculator engine tests, so the guide and interactive result share one verified calculation basis.

Reference calculation

Modular brick count by net wall area

This table keeps the coverage fixed at the BIA Modular rate of 675 brick per 100 ft² and applies a 5% allowance. It is a calculation reference, not a substitute for confirming the actual brick product or bond pattern.

If your supplier or project specification gives a different coverage rate, use that rate instead of forcing a preset that does not describe the brick being purchased.

Net area

Subtract measured openings before the brick rate

Doors and windows reduce the wall face that receives brick, so the BIA wall-area method uses gross wall area less openings. Add the measured areas of the openings that will not receive brick and subtract that total before multiplying by the coverage rate.

The BuildMeasure calculator accepts one combined openings-area input. It does not add special jamb, sill, arch, corner, or bond-maintenance units, so those project details must be checked separately when they matter.

Purchase allowance

Add waste after the net quantity is known

BIA Technical Note 10 says to determine net brick quantities before allowances are added and gives at least 5%as a general rule for brick breakage and waste. It also notes that job conditions or experience can justify a higher percentage. BuildMeasure therefore defaults to 5% but leaves the value editable.

If you know your current local price per brick, the calculator can multiply the rounded order quantity by that user-entered price. It does not fetch live prices, convert currencies, or infer tax, delivery, labor, discounts, or supplier minimums.

Scope boundary

Coverage is not the same as masonry design

BIA Table 4 quantities are based on running or stack bond. Header-containing patterns such as common, English, Flemish, or garden-wall bond require separate correction factors and are not modeled by this guide. The guide also does not estimate mortar, grout, wall thickness, wythes, anchors, reinforcement, lintels, foundations, structural capacity, or code compliance.

BIA also states that its Technical Notes are based on fired-clay brick and should not automatically be applied to concrete, fly-ash, or other non-clay units. Confirm the material and coverage data for the exact product before ordering.

Primary source: Brick Industry Association Technical Note 10. Material-scope reference: BIA Technical Notes. Unit conversions follow NIST SP 811 Appendix B.