Estimate the mortar for a brick or concrete block wall. Enter the wall area, pick the brick or block size and the joint thickness to get the mortar volume, how many bags of premix or masonry cement to buy, and the number of bricks or blocks in the wall.
Last updated:
Units
sq ft
Length × height
m²
Length × height
sq ft
m²
inches (mm in metric)
in
3/8 in = 0.375 is standard
mm
%
10–25% is typical for dropped and leftover mortar
Enter your values to see the result.
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How to use the Mortar Calculator
Choose imperial or metric and enter the wall area and any openings.
Pick the brick or block (or enter a custom size) and the joint thickness.
Choose the mortar type you will buy and a waste allowance.
Read the bags of mortar, the mortar volume and the brick or block count.
How the mortar is calculated
Units per sq ft = 144 ÷ ((L + j) × (H + j)) for a unit L × H in on the face and joint j
Mortar per unit = ((L + j) × j + H × j) × bedded depth (full depth for brick, 2 × face-shell thickness for face-shell bedded block)
Mortar = units × mortar per unit × (1 + waste)
Bags = mortar ÷ bag yield
Example: 200 sq ft of modular brick with 3/8 in joints: 6.86 bricks per sq ft → 1,371 bricks. Each brick holds (8 × 0.375 + 2.25 × 0.375) × 3.625 = 13.9 in³ of mortar, so the wall needs 11.1 ft³; with 15% waste that is 12.7 ft³, or 20 bags of 80 lb premix.
Mortar per 1,000 units (3/8 in joints, no waste)
Unit
Units per sq ft
Mortar per 1,000
Modular brick
6.86
8.1 ft³
Standard brick
6.55
8.7 ft³
Queen brick
5.76
7.0 ft³
King brick
4.80
8.2 ft³
Utility brick
3.00
12.3 ft³
8 in block (face-shell)
1.125
12.8 ft³
Real use depends on the mason, the bond pattern, how full the head joints are and how much drops. Buy an extra bag or two and return unopened ones.
Frequently asked questions
How much mortar do I need per 1,000 bricks?
For modular bricks (7 5/8 × 2 1/4 × 3 5/8 in) with 3/8 in joints the joints themselves hold about 8 ft³ of mortar per 1,000 bricks. With a typical 10–25% allowance for waste, plan on roughly 9–10 ft³, which is about 14–16 bags of 80 lb premix.
How many bricks are in a square foot?
About 6.86 modular bricks per square foot of single-wythe wall with 3/8 in joints (each brick plus joint covers 8 × 2.625 in). Queen bricks need about 5.8 and king bricks about 4.8 per square foot.
How much mortar does a concrete block need?
With face-shell bedding (mortar only on the outer shells) an 8 in block with 3/8 in joints uses about 22 in³ of mortar in its joints, or roughly 1.3 ft³ per 100 blocks before waste. Full bedding, used on the first course and in grouted walls, uses much more.
How much does an 80 lb bag of mortar mix make?
Premixed mortar in an 80 lb bag yields roughly 0.6–0.7 ft³ of mortar, depending on the brand and the water added; the calculator uses 0.65 ft³. A bag of masonry cement mixed with about three parts sand makes roughly 3 ft³. Check the yield on your bag.
How is mortar volume calculated?
Each brick or block plus its joint occupies (L + j) × (H + j) of wall face. The mortar per unit is the joint area ((L + j)·j + H·j) multiplied by the bedded depth. Multiply by the number of units, which is the net wall area divided by (L + j)(H + j), then add waste.
Which mortar type should I use?
Type N is common for above-grade walls and veneer, Type S for below-grade, retaining and high-wind work, and Type M for foundations and heavy loads. The type changes strength, not the volume you need.
Is my data sent anywhere?
No. All calculations run in your browser.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.