Mortar calculator
A wall 20 ft long and 4 ft high in modular brick takes about 17 bags of 80 lb mortar mix with 10% extra.
Where the numbers come from
QUIKRETE says an 80 lb bag of its Mortar Mix or Mason Mix lays up to 37 standard bricks or 13 standard 8 × 8 × 16 in blocks. "Up to" is the most a bag will do, so the calculator adds 10% unless you change it. Every other brick size takes more mortar per brick than modular; the calculator scales the bricks per bag by the Brick Industry Association's mortar volume for each size, from its Technical Note 10. To mix your own mortar from cement, lime and sand instead of buying bags, the cement calculator gives the bags of each.
540 × 1.1 ÷ 37 per bag = 17 bags
Mortar by brick size
| Brick | Mortar, cu ft per 1,000 (⅜ in joint) | Bricks per 80 lb bag | Bags per 1,000 bricks | Bags per 100 sq ft |
|---|---|---|---|---|
| Modular | 8.1 | 37 | 28 | 19 |
| Standard | 14.5 | 21 | 49 | 32 |
| Queen | 12.2 | 25 | 41 | 23 |
| King | 14.2 | 21 | 48 | 22 |
| Engineer modular | 8.5 | 35 | 29 | 16 |
| Closure modular | 9.1 | 33 | 31 | 14 |
| Roman | 10.7 | 28 | 36 | 22 |
| Norman | 11.2 | 27 | 38 | 17 |
| Utility | 12.3 | 24 | 42 | 13 |
The BIA also cites masons' rule of thumb that 8 bags of masonry cement lay 1,000 modular bricks. That counts bags of masonry cement, which is mixed with sand on site, not bags of preblended mortar mix; the BIA notes that 1 cu ft of loose, damp sand makes about 1 cu ft of mortar.
| Item | Typical | Range | Stores |
|---|---|---|---|
| 80 lb bag of mortar mix | $9.98 | $9.55 to $9.99 | 3 |
Sources
- QUIKRETE Mortar Mix (No. 1102) and Mason Mix (No. 1136) data sheets, The QUIKRETE Companies, revised November 2020. An 80 lb bag lays up to 37 standard bricks or 13 standard 8 x 8 x 16 in blocks.
- Technical Note 10: Dimensioning and Estimating Brick Masonry, Brick Industry Association, February 2009. Bricks per 100 sq ft of wall and cubic feet of mortar for each brick size and joint (Table 4).