Mortar Mix Calculator — How Much Mortar Do I Need?
Estimate how many 80lb bags of mortar mix you need for block walls, brick walls, stone veneer, or tuckpointing.
How to Use This Calculator
- Select your project type (block wall, brick wall, stone veneer, or tuckpointing).
- Enter the total area or number of units (blocks/bricks or square feet of surface).
- Choose your typical joint thickness.
- Adjust the waste factor if needed (15% is a safe default).
- Click "Calculate" to see how many 80lb bags of mortar you need.
How the Calculation Works
// Coverage varies by project type
// Block walls: ~33 blocks per 80lb bag
// Brick walls: ~38 bricks per 80lb bag
units_per_bag = coverage[project_type] // blocks, bricks, or sq ft
raw_bags = units / units_per_bag
bags_with_waste = ceil(raw_bags × (1 + waste_factor))
mortar_volume_cuft = bags_with_waste × 0.6 // approx. 0.6 cu ft per 80lb bag Coverage per bag depends on the project type. This calculator divides your total units or area by a typical coverage rate, then adds a waste factor and converts bags into approximate volume in cubic feet.
Variables:
- project_type: Block wall, brick wall, stone veneer, or tuckpointing
- units: Total number of blocks/bricks or square feet of surface
- waste_factor: Extra percentage to cover waste and spillage
Pro Tips
- Only mix as much mortar as you can place in about 30–45 minutes.
- Keep your mortar consistency like peanut butter—too wet and it sags, too dry and it will not bond well.
- Protect fresh mortar from direct sun, wind, and freezing temperatures.
- Use the right mortar type: Type S for structural walls, Type N for above‑grade brick and veneer (always follow code).
Recommended Mortar Tools
Type S Mortar Mix
High‑strength mortar mix for structural and below‑grade block walls.
View on Amazon →Type N Mortar Mix
General‑purpose mortar for above‑grade brick and stone veneer.
View on Amazon →Mortar Mixing Drill Attachment
Mix smaller batches of mortar quickly using a drill.
View on Amazon →Mortar Board / Hawk
Keeps mortar at a comfortable working height.
View on Amazon →Pointing Trowel
Ideal for tuckpointing and small repairs.
View on Amazon →Frequently Asked Questions
How many blocks can I lay with one bag of mortar?
On average, one 80lb bag of mortar will lay about 33 standard concrete blocks. Coverage varies with joint thickness and workmanship.
How many bricks can I lay with one bag of mortar?
A single 80lb bag of mortar can usually lay around 35–40 standard bricks. This calculator uses 38 bricks per bag as a rule of thumb.
How thick should mortar joints be?
Typical mortar joints are about 3/8" thick. Thicker joints use more mortar and may require extra bags beyond the estimate.
What type of mortar should I use?
Type S mortar is commonly used for structural block walls and below grade. Type N is often used for above‑grade brick and stone veneer. Always follow manufacturer guidance and local codes.