Mortar Calculator
Estimate masonry mortar bags for brickwork or blockwork from unit count or wall area, unit size, joint thickness, coverage per bag, and waste.
This page is for mortar between bricks or blocks. For tile grout and thinset, use the Tile Calculator. For CMU core fill, use the Concrete Block Calculator.
Results
Planning estimate only. Mortar coverage depends on unit texture, joint depth, wall thickness, tooling, dropped mortar, and product yield. Use the bag label, project specs, or supplier guidance when available.
How to use this calculator
- 01Choose Brickwork or Blockwork.
- 02Choose Unit Count if you already know the number of bricks or blocks, or Wall Area to estimate units from wall length and height.
- 03Choose a unit size preset or enter custom unit length and height.
- 04Set the mortar joint thickness.
- 05Enter coverage per bag from the product label, supplier guidance, or your usual planning rate.
- 06Add waste for dropped mortar, rough units, joint variation, and cleanup.
- 07Use Mortar Bags Needed as the order quantity. Add bag yield only if you want a rough volume for the bags you plan to buy.
If you need the brick count first, use the Brick Calculator. If you are estimating CMU or concrete block count, use the Concrete Block Calculator.
Understanding the math
Mortar bags start with unit count. You can enter the count directly, or the calculator can estimate units from wall area using the face size of the brick or block plus its mortar joint.
wall_area = wall_length x wall_height units = ceil(wall_area / ((unit_length + joint) x (unit_height + joint)))
bags_before_waste = units / coverage_per_bag bags_needed = ceil(bags_before_waste x (1 + waste_percent / 100))
estimated_mortar_volume = bags_needed x bag_yield
The coverage-per-bag input keeps the estimate honest: mortar yield changes with joint depth, wall thickness, unit texture, tooling, and product mix. The bag label or supplier guidance should override the default coverage.
Mortar reference table
Common planning values for brick and block mortar. Use product labels, plans, or supplier guidance when they give more specific coverage.
| Item | Planning value | Note |
|---|---|---|
| Brick coverage | Enter bricks / bag | Use the bag label or supplier rate |
| Block coverage | About 33 blocks / bag | Common 3 bags per 100 blocks rule |
| Typical joint | 3/8 in | Thicker joints can use more mortar |
| Waste | 5-10% | Dropped mortar, rough units, cleanup |
| Type N | General-purpose | Common non-structural masonry use |
| Type S | Stronger mix | Often exterior, structural, or below grade |
Frequently asked questions
How much mortar do I need?
Mortar quantity depends on the brick or block count, unit size, mortar joint thickness, coverage per bag, and waste. Enter the unit count directly, or estimate the units from wall area, then divide by your product's coverage per bag and round up.
How do I calculate mortar?
Estimate the number of bricks or blocks, divide that count by the coverage per bag, add waste, and round up to whole bags. Product labels and supplier guidance should override the default coverage when they give a different yield.
How do I calculate mortar for brickwork?
Use the brick count when you already have it. If you only know the wall size, estimate bricks from wall area, brick face size, and mortar joint thickness first. Then divide the brick count by bricks per bag and add waste.
How do I calculate mortar for blocks?
Use the block count or estimate blocks from wall area. A common planning rule for standard concrete blocks is about 3 mortar bags per 100 blocks, or about 33 blocks per bag, but the product label and joint conditions matter.
How many bricks per 80 lb bag of mortar?
It depends on brick size, joint thickness, wall thickness, brick texture, and product yield. Use the bag label when it lists brick coverage, or enter your own bricks-per-bag coverage in the calculator.
What is the difference between Type N and Type S mortar?
Type N is a common general-purpose mortar for many non-structural masonry jobs. Type S is stronger and is often used for exterior, structural, or below-grade work. Follow the plans, local code, or product guidance for the right mortar type.
Is this the same as grout or thinset?
No. This page estimates masonry mortar between bricks or blocks. Tile grout and thinset belong in the Tile Calculator, while CMU core grout or concrete fill belongs in the Concrete Block Calculator.
Can I use this calculator with metric measurements?
Yes. Use the Imperial/Metric toggle. Inputs, results, reference values, and examples follow the active unit system where applicable.
Related calculators
Brick Calculator
Estimate brick count from wall area, openings, brick size, mortar joint, waste, and optional price per brick.
Concrete Block Calculator
Estimate concrete blocks, cinder blocks, CMU wall materials, mortar bags, and optional fill.
Square Footage Calculator
Calculate wall or surface area first, then use wall area mode for mortar.