Mortar Calculator
Find how many bags of mortar you need for bricks or concrete blocks.
Tell us about your wall
Your answer
To lay 567 modular bricks, with 15% extra mortar.
Or mix your own
5 bags of masonry cement (70 lb) and 1,200 lb of mason sand. That is about 105 shovels, if damp, loose sand weighs 80 lb a cubic foot (CMHA).
This answer is a guide. For walls that hold weight or hold back soil, check your local building rules or ask a builder or engineer.
What it costs
Type N: $10.80, the middle of only 3 stores. Type S: $9.59, the middle of 7 stores (Oct 2026). An 8 in block: $2.84, the middle of 4 stores. We found too few brick prices to give one.
Quick answers
- A 20 × 4 ft brick wall
- 567 modular bricks and 18 bags of 80 lb mix, extras included.
- The same wall in blocks
- 95 blocks, 8 in wide, and 9 bags of mix, extras included.
- Which type?
- Type N for most walls above ground. Type S for walls that hold weight. Most guides say S or M for retaining walls, not N.
- Water per bag
- About 5 quarts for an 80 lb bag. Makers give 4.5–6 quarts.
How to work it out
- Multiply the wall's length by its height, in feet.
- Multiply by bricks or blocks per sq ft. Add 5% for broken ones.
- Divide by how many one bag lays. Add 15% for waste, then round up.
20 × 4 = 80 sq ft of modular brick
80 × 6.75 + 5% = 567 bricks
567 ÷ 37 + 15% = 17.62 → 18 bags
Water: 18 × 5 = 90 quarts (22.5 gallons)
Or mix your own: 5 bags of masonry cement + 1,200 lb of sand
Type N, S or M?
Under the ASTM strength rule, each type has a lowest strength at 28 days. It is given in pounds per square inch (psi).
- Type N: 750 psi. Most walls above ground: garden walls, brick on a house front, chimneys.
- Type S: 1,800 psi. BIA picks it for walls that hold weight. Bag makers and the ASTM table also use it below ground.
- Type M: 2,500 psi, the strongest. BIA says Type M is strong but not very workable.
CMHA says foundation walls need M or S. Sakrete sells its Type N for above ground only.
The guides don't agree on every first choice:
| Use | BIA | ASTM table | Argos |
|---|---|---|---|
| Wall above ground that holds weight | S (or N) | N (or S, M) | S |
| Foundation or retaining wall | M (or S) | S (or M, N) | S or M |
| Chimney | N (or S) | N (or S) | S |
First choice, then others in brackets. BIA is the Brick Industry Association. Lehigh prints the ASTM table.
Only the ASTM table lists N for a retaining wall, and only as a last choice. For walls that hold weight or hold back soil, check your local building rules or ask a builder or engineer.
Bricks or blocks?
Bigger bricks and wider blocks take more mortar each. "One bag lays" is the bag makers' count, as in the calculator.
| Brick or block (how many) | One bag lays | Bags, no extra | Bags to buy (extra) |
|---|---|---|---|
| Modular brick (1,000) | 37 | 27 | 32 (+15%) |
| Utility brick (1,000) | 22 | 45.5 | 46 (+0%) |
| 8 in block (100) | 12.5 | 8 | 10 (+15%) |
| 12 in block (100) | 9 | 11.1 | 12 (+0%) |
Modular brick and 8 in block use Quikrete's and Sakrete's counts, so we add 15%. The others are SPEC MIX's low end, with waste already in.
- Full brick chart: brick mortar calculator
- Block widths: block mortar calculator
Bagged mix or mix your own
Mortar mix in a bag
Mortar mix (premix) already has the sand in it. Just add water, about 5 quarts a bag. One 80 lb bag makes about 0.75 cubic feet, the middle of 3 makers' sheets.
Masonry cement and sand
Or mix masonry cement with mason sand. Quikrete uses 1 part masonry cement to 3 parts mason sand. One 70 lb bag with 240 lb of sand makes about 2.75 cubic feet.
CMHA puts damp, loose sand at about 80 lb a cubic foot, so 240 lb is about 3 cubic feet. CMHA also says 1 cubic foot is about 7 shovels. So plan about 21 shovels per bag.
Our sand calculator uses Caterpillar's heavier figure, about 106 lb a cubic foot. By that, 240 lb is about 2.3 cubic feet, or 16 shovels.
Pallets and prices
- 80 lb mortar mix: 42 bags per pallet (Quikrete).
- 70 lb masonry cement: 40 bags per pallet (Quikrete).
- Type S, 80 lb: $9.59, the middle of 7 stores (Oct 2026).
- Type N, 80 lb: $10.80, the middle of only 3 stores. Treat it as rough.
Why mortar answers differ
Bag makers count bricks or blocks per bag. BIA and the cement maker Lehigh give cubic feet of mortar instead.
Bricks: BIA gives 8.1 cubic feet for 1,000 modular bricks, with no waste. That fills about 10.8 bags. Bag makers say about 27 bags. That is about 2.5 times as much.
Blocks: it goes the other way. Lehigh's figure, with no waste, works out to about 9.4 blocks per bag. Quikrete and Sakrete say 12–13. Other bag makers say 10 to 15.
We use the bag makers' counts. We add 15% for waste unless the count already has it. BIA says mortar waste runs 15–25%.
Questions people ask
How much mortar do I need?
A 20 × 4 ft wall of modular brick takes 18 bags of 80 lb mix, with 15% extra. Type your own wall above, in bricks or blocks.
How many shovels of sand per bag of mortar?
Bagged mortar mix needs no sand. For a 70 lb bag of masonry cement, Quikrete says 240 lb of sand. At CMHA's sand weight, that is about 21 shovels.
Does Type S mortar need sand?
Not if you buy it as mortar mix. Premix mortar already has sand in it. Just add water. Masonry cement is different: you add the sand.
How many bags of mortar are on a pallet?
Quikrete puts 42 bags of 80 lb mortar mix on a pallet. Its 60 lb bags come 56 to a pallet, and 40 lb bags 80.
How much water for a 60 lb bag of mortar?
Quikrete says about 3.75 quarts. For an 80 lb bag, about 5 quarts. Add it slowly.
What mortar should I use for a retaining wall?
Most guides say S or M for retaining walls, not N. Check your local building rules or ask a builder or engineer.
Where our numbers come from
- Bricks per square foot and mortar waste: Brick Industry Association (TN 10)
- Which mortar type: Brick Industry Association (Technical Note 8B)
- Blocks, mortar, sand and core fill: Concrete Masonry & Hardscapes Association (TEK 04-02A)
- Foundation walls need Type M or S: Concrete Masonry & Hardscapes Association (TEK 09-01A)
- Mortar per block: Quikrete Mortar Mix data sheet
- Mortar bags per pallet: Quikrete Mortar Mix product page (80 lb: 42)
- Mortar per block: Sakrete Type S bag (about 12 blocks per 80 lb bag)
- Type N mortar: Sakrete data sheet (above ground only)
- Bricks and blocks per bag by size: SPEC MIX data sheet (counts include waste)
- Blocks per bag by width: TCC Materials table (2025)
- Mortar per bag: Amerimix AMX 500 data sheet (80 lb makes about 0.78 cubic feet)
- Mortar per bag: Mutual Materials DesignMix data sheet (about 0.74 cubic feet)
- Mortar per bag: TCC Materials Tech-Mix Type S data sheet (about ¾ cubic foot)
- Brick sizes: Glen-Gery brick size guide
- Mix your own mortar: Quikrete Masonry Cement data sheet (1 bag + 240 lb sand)
- Masonry cement mix and pallet: Quikrete Masonry Cement product page
- Sand per bag of masonry cement: Argos Brick-Lok (2¼–3 cubic feet)
- Sand per bag of masonry cement: Lehigh White Masonry Cement data sheet
- Material weights: Caterpillar earthwork tables
- Type N mortar price: the middle of 3 stores, 80 lb bag (Oct 2026)
- Block and mortar prices: the middle of 4 stores (blocks) and 7 stores (mortar), Oct 2026
- Brick prices seen: 2 US stores, $0.74–1.30 a brick (Oct 2026; too few for a default)
Made by BuildersCount. Last checked 3 Oct 2026.
How we work out our numbers About us Found a mistake? Tell us