Worked example: a 16 × 3 ft single-skin brick wall
Hypothetical educational example of a single-skin US modular wall. Mortar uses QUIKRETE’s published maximum of 37 standard bricks per 80 lb bag, then the calculator’s own 10%. The page does not decide whether a 3 ft wall is tall enough to need piers.
Inputs
| Wall | 16 ft × 3 ft |
|---|---|
| Openings | 0 |
| Brick | US modular |
| Joint | blank, so 3/8 in |
| Skins | 1 |
| Brick waste | 5% |
Arithmetic
- Area = 48 sq ft. Module = 144 ÷ (8 × 2.625) = 6.857 bricks per sq ft.
- 48 × 6.857 × 1.05 = 345.6, which rounds up to 346 bricks.
- Mortar is based on about 329 reference bricks of theoretical joint, not on 346.
- 329 × 1.10 ÷ 37 = 9.79, which rounds up to 10 bags.
Required, waste and purchase
- Required
- 345.6 bricks before the final roundup, and 9.79 bags of mortar before that line rounds up.
- Purchased
- 346 bricks and 10 × 80 lb bags. The extra bricks in the 5% are not what the mortar line divides by 37.
- Units
- US feet and inches, modular brick, 80 lb bags.
Assumptions
- “Up to 37” is a maximum on the data sheet. A wall can use more mortar than the maximum yield implies.
- UK and Australian bricks use different face sizes on the same calculator. This example does not convert them.
What this example does not decide
- Not a retaining wall, a structural pier layout, or a double-skin wall.
- No separate mortar calculator is published. The bag count is the mortar line of the brick result.
Where to go next
- Brick calculator — Run these inputs
- Concrete block calculator — Different module and a 13-block mortar yield
- Masonry topic — Face-plus-joint method
- Masonry calculators — Tool list
Questions
Why isn’t mortar 346 ÷ 37?
346 includes 5% for cuts and breakage. The mortar line uses the theoretical joints, about 329 reference bricks, then adds 10% and divides by 37. That is 10 bags, not 346 ÷ 37.
Is a 3 ft wall approved by this example?
No. Three feet is below the calculator’s warning threshold for a single skin, and the example still does not approve the wall. Height, piers and reinforcement are a design this site does not make.
Sources
- QUIKRETE Mortar Mix data sheet No. 1102 — accessed 2026-11-09: “Each 80 lb (36.2 kg) bag of QUIKRETE Mortar Mix will lay up to 37 standard bricks or 13 standard (8 in by 8 in by 16 in) blocks.”