How it works
The calculator takes the wall area, subtracts the openings, multiplies by the number of bricks per unit of wall area, and adds waste.
Net area = Length × Height − Openings
Bricks per area (modular) = 6.75 per sq ft
Bricks per area (custom) = 1 ÷ ((Brick length + Joint) × (Brick height + Joint))
Bricks = ⌈ Net area × Bricks per area × (1 + Waste ÷ 100) ⌉
The modular figure comes from BIA Technical Note 10: a modular brick plus its joint covers a nominal 8 × 2⅔ in, which is 21⅓ sq in, and 144 ÷ 21⅓ = 6.75 bricks per square foot. For a custom brick, each brick plus its share of mortar covers its actual length plus one joint by its actual height plus one joint.
⌈ ⌉ means rounding up to the next whole brick, done only at the end. The result is a material quantity, not a wall design.
Worked example
Inputs
- Wall length
- 20 ft
- Wall height
- 8 ft
- Brick size
- US modular (7⅝ × 2¼ in, ⅜ in joint)
- Waste allowance
- 5 %
Result
- Wall area to brick
- 160 sq ft
- Bricks per wall area
- 6.75 / sq ft
- Bricks
- 1,134
Common mistakes
- Entering the nominal brick size in the custom fields. Nominal sizes already include the joint; adding the joint again undercounts. Use the actual size, or choose modular.
- Not subtracting doors, windows and other openings – or subtracting them and then forgetting extra bricks for sills, returns and soldier courses around them.
- Ordering without waste. The Brick Industry Association’s Technical Note 10 recommends allowing at least 5 % for waste; chipped units and cuts at openings and corners come out of the same order.
- Mixing bricks from different production runs. Color can vary between runs; buy enough at once and blend from several pallets as you lay.
Assumptions and limits
- The wall is a flat rectangle. Gables, curves and steps are not modeled – split them into rectangles and add the results.
- One wythe (one brick thick) in running bond, laid as stretchers. Other bonds and multi-wythe walls use more bricks.
- Modular brick uses BIA Technical Note 10’s figure of 6.75 bricks per square foot of wall. Custom bricks use the actual size plus one joint in each direction.
- Bricks are rounded up to whole bricks after waste. Mortar, wall ties, flashing and lintels are not included.
- This is a material estimate only. Wall design, footings, ties and structural or code questions need a qualified professional.
Frequently asked questions
How many bricks are in a square foot of wall?
For US modular brick, the Brick Industry Association’s Technical Note 10 gives 675 bricks per 100 sq ft, or 6.75 per square foot, in a single-wythe running bond wall with ⅜ in joints. Other sizes differ – choose “Custom” and enter your brick’s actual size.
What is a modular brick?
A brick sized to fit a 4 in grid once the mortar joint is added. BIA lists its actual size as 3⅝ × 2¼ × 7⅝ in, laid with ⅜ in joints to a nominal 4 × 2⅔ × 8 in.
How much waste should I allow for brick?
BIA Technical Note 10 says at least 5 percent. Walls with many openings, corners or cut courses may need more; ask your mason or supplier.
Does this calculator work for a double brick wall?
Not directly. It counts a single wythe. For two wythes of the same brick, the face count roughly doubles, but headers, ties and the wall design change the real number – get that from whoever designs the wall.
How much mortar will I need?
This calculator doesn’t estimate mortar. Use the coverage stated by your mortar manufacturer, which depends on the brick size, joint thickness and how the bricks are laid.
Sources
- Technical Note 10 – Dimensioning and Estimating Brick Masonry — Brick Industry Association. Modular brick 3⅝ × 2¼ × 7⅝ in with ⅜ in joints, nominal 4 × 2⅔ × 8 in; 675 bricks per 100 sq ft (Table 4); waste "at least 5 percent".
- NIST Handbook 44, Appendix C – General Tables of Units of Measurement — National Institute of Standards and Technology. Exact unit definitions: 1 in = 2.54 cm, 1 yd³ = 27 ft³, 1 US gal = 231 in³, 1 lb = 0.45359237 kg.
Method reviewed November 2, 2026