How to work out your mortar
Mortar is counted from the units, not from the wall. So start with how many bricks or blocks you are laying. If you only know the size of the wall, use the brick calculator or the concrete block calculator first, then come back with the count.
Then look at the bag, because this is where most estimates go wrong. A preblended bag, such as Quikrete Mortar Mix, needs only water. A bag of masonry cement needs sand added as well, and it lays several times more units. A rule of thumb written for one is badly wrong for the other, so check which you are holding.
Then choose the type. General Shale says Type N for typical walls above grade, and Type S for below grade and block foundations and pavers. Quikrete lists 750 psi for N, 1800 for S and 2500 for M. For anything structural, your local code decides.
A worked example
Here is a wall of 130 standard blocks in 80 pound bags. These lines come from the same formula the calculator above runs.
130 blocks, 80 lb bags
- At the bag's yield: 130 ÷ 13 = 10 bags
- At the association's yield: 130 ÷ 16 rounds up to 9 bags
- Mixing your own, Type N: 3 bags of portland cement and 2 of lime
- With 0.50 tons of sand
The two yields are about a fifth apart. Quikrete says up to 13, and CMHA's 16 assumes face shell bedding. A full bed takes more, and a first-timer's joints tend to be fatter. If you can return unopened bags, buy to the lower yield. For the footing below it, see the concrete calculator.
Mortar for common jobs
These count only the units, so your own count may differ by the waste you allow. The gap between the columns is the real uncertainty in any estimate of this kind.
| Job | Units | 80 lb bags, the bag's yield | 80 lb bags, association |
|---|---|---|---|
| Short garden wall, block | 50 | 4 | 4 |
| Shed wall, block | 180 | 14 | 12 |
| Garage, block | 500 | 39 | 32 |
| Planter, brick | 200 | 6 | 4 |
| Low wall, brick | 500 | 14 | 10 |
| Long wall, brick | 2000 | 55 | 40 |
Mistakes that run you short of mortar
- Mixing up the bags. The rule of 3 bags per 100 block is masonry cement plus sand. Preblended takes about 6 to 8.
- Treating a yield as a promise. The sheet says up to. Skill, corners and returns all use more.
- Face shell or full bed. CMHA's block yield assumes face shell bedding, and a full bed uses more.
- The wrong type below grade. Type N is for typical walls above grade. Foundations and below-grade work want S or more.
- Forgetting the sand. Masonry cement and portland cement both need sand added, and at volume that means a delivery.
Questions
How many bricks does one bag of mortar lay?
Up to 37 standard bricks for an 80 pound bag of Quikrete Type N or Type S, by its data sheet. CMHA's TEK 04-02A says 50 brick-sized units. Masonry cement bags with added sand lay far more, about 143 modular bricks, so check which bag you mean.
How many blocks per 80 lb bag of mortar?
Up to 13 standard 8 by 8 by 16 inch blocks, by Quikrete. CMHA's table says 16 with face shell bedding. We start from 13 because running out is the worse mistake, and a full bed uses more.
How many bags of mortar per 100 block?
About 8 bags of 80 pound preblended mortar, at Quikrete's 13 blocks per bag, or 7 at CMHA's 16. General Shale's rule of 3 bags per 100 blocks is for masonry cement, which needs sand added too. It is a different product.
Type N or Type S?
Type N for typical walls above grade, and Type S for below grade and block foundations, as General Shale puts it. Quikrete lists 750 psi for N and 1800 for S. Check what your local code asks for on anything structural.
How much sand and cement to mix my own?
For Type N, 1 part portland cement, 1 part lime and 6 parts sand by volume lays 62 blocks or 300 bricks, by CMHA's table. Type S uses 1, 1/2 and 4-1/2. A ton of damp loose sand is about 25 cubic feet.
Is mortar the same as thinset?
No. Masonry mortar binds bricks and blocks, while thinset is a tile adhesive, and they are not interchangeable. Search results mix them up, so read the bag. If you are setting tile, use the thinset calculator.
This mortar count is a planning estimate from yields that say up to, and skill, joint width and bedding method all change them. Choose the type your wall needs, since a foundation is not a garden wall, and read the label on the bag. A cement-only bag needs aggregate added, so check with your supplier, and do not confuse any of this with thinset.
Sources and review
- Mortar Mix 1102 data sheet, Quikrete, 2020.
- Mason Mix 1136 data sheet, Quikrete, 2020.
- TEK 04-02A, estimating concrete masonry materials, Concrete Masonry and Hardscapes Association, no date shown, read November 2026.
- Rule of thumb figures, General Shale Brick, 2024.
Checked in November 2026. Spotted a wrong number? Report it and it goes in the corrections log.
How this is calculated
Every figure below is read from the code that produces the answer, so what is written here is what the calculator ran. The constants were last checked against their sources in November 2026.
The arithmetic
Bags
Bags = Units ÷ Units per bag, rounded up
- Units per bag
- 13 blocks or 37 bricks for an 80 lb bag, by Quikrete
Worked through: 130 ÷ 13 = 10 bags
Mixing your own, Type N
Batches = Units ÷ Units per batch
- Units per batch
- 62 blocks or 300 bricks, for 1 cu ft cement, 1 cu ft lime and 6 cu ft sand
Worked through: 620 ÷ 62 = 10 batches
The constants, and where they come from
YIELD_80_LB
Published figureUnits laid by one 80 lb preblended bag, by source
- maker
- brick 37, block 13
- association
- brick 50, block 16
Applies to: Standard bricks and 8 × 8 × 16 in blocks. Face shell or full bedding changes it
Source: Mortar Mix 1102 data sheet, Quikrete, published 2020-11, read 2026-11. This source is about 6 years old, and it is the one the figure rests on.
Also from: Mason Mix 1136 data sheet, Quikrete, published 2020-11, read 2026-11.
Also from: TEK 04-02A, estimating concrete masonry materials, Concrete Masonry and Hardscapes Association, no date on the page, read 2026-11.
Quikrete states up to 37 bricks or 13 blocks for Type N and Type S alike. CMHA's table says 50 and 16 with nominal waste. We start from the lower one, and offer both.
STANDARD_BAG_POUNDS
Published range, narrowedThe bag size the yields are written for, in pounds
Applies to: Scaling to a 40 or 60 lb bag
Source: Mortar Mix 1102 data sheet, Quikrete, published 2020-11, read 2026-11. This source is about 6 years old, and it is the one the figure rests on.
Quikrete states only the 80 lb yield. Scaling smaller bags by weight is our own assumption.
SITE_MIX
Published figureOne batch of site-mixed mortar: cubic feet of lime and sand per cubic foot of portland, and the units it lays
- N
- lime 1, sand 6, brick 300, block 62
- S
- lime 0.5, sand 4.5, brick 225, block 46
- M
- lime 0.25, sand 3.75, brick 187, block 38
Applies to: Mixing your own, by type
Source: TEK 04-02A, estimating concrete masonry materials, Concrete Masonry and Hardscapes Association, no date on the page, read 2026-11.
TEK 04-02A Table 2. Type N has 1 of lime and 6 of sand, Type S 1/2 and 4-1/2, and Type M 1/4 and 3-3/4.
LIME_BAG_CU_FT
Published figureCubic feet in one 50 lb bag of lime
Applies to: Hydrated lime
Source: TEK 04-02A, estimating concrete masonry materials, Concrete Masonry and Hardscapes Association, no date on the page, read 2026-11.
A note to TEK's Table 2. A 94 lb bag of portland cement is 1 cubic foot, by the same note.
SAND_CU_FT_PER_TON
Published figureCubic feet in one ton of damp loose sand
Applies to: Damp loose masonry sand
Source: TEK 04-02A, estimating concrete masonry materials, Concrete Masonry and Hardscapes Association, no date on the page, read 2026-11.
A note to TEK's Table 2, which puts damp loose sand at 80 pounds per cubic foot.
What the labels mean
- Published figure:
- taken directly from the source named beside it.
- Published range, narrowed:
- a source publishes a range and this calculator uses a representative value from it.
If a figure here looks wrong, it may be. Tell us what you found and we will check it against the source and publish a correction if it needs one. How constants are chosen and how often they are reviewed is set out in our methodology.
How to use the mortar calculator for brick and block
- 1
Count your bricks or blocks, or get the count from their calculator
- 2
Choose the bag size you can lift
- 3
Start with the bag's yield, and try the association's for comparison
- 4
Read the bags, or the materials to mix your own
- 5
Check the type against what your wall has to do
What this calculator assumes
Every estimate here rests on the assumptions below. Where your job differs from one of them, the figure will differ too.
- Standard bricks and 8 × 8 × 16 inch blocks, in common joints
- It starts from the bag's own yield, which is lower than the association's
- Smaller bags are scaled by weight, which is our assumption, since makers state only the 80 lb yield
- Site-mix amounts are for one type at a time, and they use the batch sizes in TEK 04-02A
Pro tips
- Mix only what you can use, and follow the bag for how long it stays workable
- Keep your joints even, as thicker joints use mortar much faster
- Buy one extra bag for a color-critical job, because batches can differ