How many bags of mortar for a block or brick job — from the count or the wall SF. For block it also gives the site-mix: masonry cement and sand, or portland, lime and sand (NCMA TEK 4-2A).
Mortar calculator
32 bags of mortar500 block · 16 per 80 lb bag
- Units
- 500 block
- 80 lb bags (preblended)
- 32 bags
- Or masonry cement + sand
- 17 × 70 lb bags + 2.08 tons sand
- Or Type N: portland + lime + sand
- 9 × 94 lb portland + 7 × 50 lb lime + 1.79 CY sand
These sketches are here to help you order material and price the work quickly. They are not engineered or shop drawings — always build from your approved project drawings.
Face-shell bedding; TEK says the same for every block width. Half-high block count as half a standard block.
Site mix type (portland + lime)TEK 4-2A Table 2 per 94 lb bag of portland: M ¼ ft³ lime + 3¾ sand ≈ 38 block · S ½ + 4½ ≈ 46 · N 1 + 6 ≈ 62 · O 2 + 9 ≈ 93.
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Show the math▾
- Bags of mortar (80 lb)block ÷ block per bag, rounded up500 ÷ 16 = 32
- Or site mix: masonry cement (70 lb bags)block ÷ 30, rounded up500 ÷ 30 = 17
- Sand for masonry cement (tons)block ÷ 240 per ton500 ÷ 240 = 2.08
- Or site mix: portland (94 lb bags)block ÷ 62 per batch (1 bag), rounded up500 ÷ 62 = 9
- Hydrated lime (50 lb bags)batches × 1 ft³ ÷ 1.25 ft³ per bag, rounded up500 ÷ 62 × 1 ÷ 1.25 = 7
- Sand for portland-limebatches × 6 ft³500 ÷ 62 × 6 ft³ = 48.39 ft³
Where the numbers come from
- Standard block per SF: 144 ÷ (16 × 8) = 1.125 per SF; a half-high block is half a standard unitSame as the CMU page: worked out from the nominal 8" × 16" face, which already includes the ⅜" joint.Source
- Block per 80 lb bag: TEK 4-2A: about 16 standard block per 80 lb bag of preblended mortar (face-shell bedding) · QUIKRETE Mason Mix: up to 13TEK 4-2A Table 2 (the CMU page uses the same 16). QUIKRETE's Mason Mix data sheet says up to 13 standard 8×8×16 block per 80 lb bag — use the number your bag prints. TEK says the estimate is the same for every block width.Source
- Site-mixed mortar for block: Masonry cement: 70 lb bag ≈ 30 hollow units; 1 ton sand per 8 bags (≈ 240 units per ton) · Portland-lime (Table 2): per 94 lb portland bag, Type N 1 ft³ lime + 6 ft³ sand ≈ 62 units; Type S ½ + 4½ ≈ 46NCMA TEK 4-2A Table 2 (face-shell bedding, includes nominal waste). Portland-lime per 1 ft³ bag of portland: Type M ¼ ft³ lime + 3¾ ft³ sand ≈ 38 block; S ½ + 4½ ≈ 46; N 1 + 6 ≈ 62; O 2 + 9 ≈ 93. A 50 lb lime bag is 1¼ ft³ (Table 2 footnote). TEK adds ½ ton of sand for waste on jobs over 3 tons — enter waste if you want it.Source
- Brick per SF: The brick page's count: 144 ÷ (course height × (length + joint)), running bondBIA Technical Note 10 sizes with ⅜" joints — the same math as the brick calculator.Source
- Brick per 80 lb bag: SPEC MIX Masonry Cement & Sand: 39–41 modular brick per 80 lb bag (typical waste included) → 39 × 8.1 ÷ 1000 = 0.316 ft³ of joint per bagSPEC MIX data sheet, estimated yields: modular 39–41, queen 33–35, king 26–28, utility 23–25 per 80 lb bag. The page takes modular's low end, 39, with BIA's 8.1 ft³ per 1000 modular brick, and divides every brick's BIA mortar by it. Change it to the number on your bag.Source
- Mortar volume: BIA Technical Note 10, Table 4: ft³ of mortar per 100 SF, ⅜" joints, no wasteThe same figures as the brick page (modular 5.5, Norman 5.1, utility 3.7, queen 6.7, king 6.5, standard 9.5 ft³ per 100 SF …). BIA suggests 15–25% mortar waste — enter it under Adjust.Source
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