Mortar Calculator
Enter the wall area or the number of units you are laying and this calculator returns the mortar to buy: bags, sand for a site-mixed batch, and mixing water. Every yield comes from a published source — NCMA's estimating tables for block, the Brick Industry Association's mortar volumes for brick, the data sheet for bagged mix.
Results are estimates for planning purposes. Verify with your supplier, engineer, or a qualified professional before ordering material or performing work.
Published mortar yields
| Mortar | Conventional block | Brick-sized units | Per 100 block |
|---|---|---|---|
| 70 lb bag masonry cement + sand | 30 | 1,000 | 4 bags + 0.4 ton sand |
| 80 lb bag preblended mortar | 16 | 50 | 7 bags |
| 3,000 lb bulk bag preblended | 420 | 1,550 | 0.24 bulk bag |
| 80 lb bag QUIKRETE Mason Mix | 13 | 37 standard bricks | 8 bags |
First three rows: NCMA TEK 4-2A Table 2 — face shell bedding for conventional block, full bedding for brick-sized units, nominal waste included. Last row: QUIKRETE Mason Mix No. 1136 data sheet. The spread between the preblended figures is real: it depends on the bag, the mason and the joint, which is why the yield printed on your product wins over any calculator.
Mortar volume for brick
| Brick | Per 1,000 brick, 3/8 in joint | 1/2 in joint | Per 100 ft² of wall, 3/8 in |
|---|---|---|---|
| Modular | 8.1 ft³ | 10.3 ft³ | 5.5 ft³ |
| Standard | 14.5 ft³ | 17.8 ft³ | 9.5 ft³ |
| Queen | 12.2 ft³ | 13.5 ft³ | 6.7 ft³ |
| King | 14.2 ft³ | 16.0 ft³ | 6.5 ft³ |
| Utility | 12.3 ft³ | 15.7 ft³ | 3.7 ft³ |
BIA Technical Notes 10 Table 4 — the theoretical volume of mortar in the wall for fully bedded solid units, before waste. BIA's own instruction is to add 15 to 25%. Note how much more mortar the published figures give to non-modular sizes at the same joint thickness: that is what the table says, and it is one more reason to price the mortar off the size you are actually buying. Full brick line-up in the brick calculator.
Mortar types and site-mix proportions
| Type | Portland cement-lime proportions (by volume) | Conventional block per batch | Minimum compressive strength, ASTM C270 |
|---|---|---|---|
| M | 1 ft³ cement : ¼ ft³ lime : 3¾ ft³ sand | 38 | 2,500 psi |
| S | 1 ft³ cement : ½ ft³ lime : 4½ ft³ sand | 46 | 1,800 psi |
| N | 1 ft³ cement : 1 ft³ lime : 6 ft³ sand | 62 | 750 psi |
| O | 1 ft³ cement : 2 ft³ lime : 9 ft³ sand | 93 | — |
Proportions and units-per-batch: NCMA TEK 4-2A Table 2. Strengths: the property requirements of ASTM C270 as published on the QUIKRETE Mason Mix data sheet. Which type your wall needs is a specification decision — ASTM C270 Appendix X1 is the guidance document, and the answer comes from your drawings, not from a calculator. Field conversions from NCMA: a bag of portland cement is 1 ft³ and 94 lb; a bag of mason's lime is 1¼ ft³ and 50 lb; a ton of damp loose sand is about 25 ft³, and 1 ft³ of sand is roughly seven shovelfuls.
On the wall
- Mortar is not grout, and neither is concrete. Mortar goes in the joints, grout fills the cells, concrete goes in forms. They are three products with three consistencies and three specifications.
- Face shell or full bed changes the number. NCMA's block yields assume face shell bedding — mortar on the two face shells only. Full bedding, which brick-sized units and the first course get, uses noticeably more.
- Mix it long enough. QUIKRETE calls for a minimum of five minutes of mixing, and the consistency test is a half-inch layer that stays on a trowel held near vertical.
- Water past the maximum costs strength. The data sheet's maximum expected water content is below 7 quarts for an 80 lb bag. Retempering water is not free.
- Order the last bag you think you need, plus one. Every published yield in this page carries the caveat that the mason's skill, corners, returns and non-modular layout move the number.
How it's calculated
- Units from wall area
units = area (ft²) / unit face area (ft²)Nominal face areas: 8/9 ft² for a conventional block, 4/9 ft² for a half-high or half-length block, 4/27 ft² for a brick-sized unit. Brick counts come from BIA Table 4: 675 modular, 655 standard, 550 queen, 455 king or 300 utility per 100 ft².- Bags of mortar for block
bags = ceiling( units × (1 + extra % / 100) / units per batch )Units laid per batch, face shell bedding: 30 conventional block per 70 lb bag of masonry cement, 16 per 80 lb preblended bag, 420 per 3,000 lb bulk bag, 13 per 80 lb bag of QUIKRETE Mason Mix. Brick-sized units are laid in a full bed: 1,000, 50, 1,550 and 37 respectively.- Sand for a site-mixed batch
sand (tons) = units / 240 ; 1 ton damp loose sand = 25 ft³NCMA: 1 ton of masonry sand per 8 bags of masonry cement, about 240 conventional units per ton; above 3 tons add half a ton for waste.- Mortar volume for brick
mortar (ft³) = brick / 1000 × ft³ per 1000 brick × (1 + extra % / 100)BIA Table 4, theoretical mortar in the wall before waste: modular 8.1 ft³ per 1,000 at a 3/8 in joint and 10.3 at 1/2 in; standard 14.5 and 17.8; queen 12.2 and 13.5; king 14.2 and 16.0; utility 12.3 and 15.7. BIA's instruction is to add 15 to 25% for waste.- Mixing water
water = 5 qt per 80 lb bag of QUIKRETE Mason Mix (7 qt maximum), 3¾ qt per 60 lb bag (5¼ qt maximum)From the data sheet. Mix at least 5 minutes; the mortar is right when a 1/2 in layer stays on a trowel held near vertical.
Frequently asked questions
Sources & references
- NCMA TEK 4-2A — Estimating Concrete Masonry Materials (2004), Tables 1 and 2: units per 100 ft², units laid per batch of mortar, sand per bag of masonry cement, mortar proportions for Types M, S, N and O — Published by the National Concrete Masonry Association, now the Concrete Masonry & Hardscapes Association (CMHA).
- Brick Industry Association — Technical Notes 10, Dimensioning and Estimating Brick Masonry (February 2009), Table 4 and the waste guidance: brick per 100 ft², cubic feet of mortar per 1,000 brick, 15 to 25% mortar waste
- QUIKRETE Mason Mix (Type S Mortar) No. 1136 — product data sheet, revised November 2020: 13 standard 8 × 8 × 16 blocks or 37 standard bricks per 80 lb bag, mixing water and maximum water content, ASTM C270 and C1714
Content checked against these sources — last reviewed August 29, 2026.