Mortar Calculator
Estimate the number of mortar bags for a brick or block project using the masonry-unit count and the coverage stated for the exact mortar product you plan to buy.
Continue your project estimate
Calculate brick quantity for this masonry project →Mortar bag formula
This calculator does not hide a universal “bricks per bag” assumption. Mortar yield changes with unit dimensions, bed and head joints, joint profile, workmanship and the product itself. Enter the coverage published for your bag.
bags = ceil(units × (1 + extra %) ÷ units covered per bag)
The result is rounded up because mortar is normally purchased in whole bags.
Brick mortar calculator workflow: count units, then apply bag coverage
If you do not yet know the masonry-unit quantity, first calculate the wall units from measured area and the dimensions of the material. For face brick, the Brick Calculator uses the repeating brick-and-joint module. Concrete block and other masonry systems may require a project-specific takeoff.
Once you have the unit count, use the mortar manufacturer’s coverage chart or technical data for the selected product and joint configuration. Keeping unit count and bag coverage separate makes the estimate easier to audit than a hidden “bags per wall” shortcut.
Why real mortar use can differ
Waste, dropped mortar, uneven substrates, filled cells, reinforced details, unusually deep joints and site conditions can increase consumption. This tool estimates bag quantity only; it does not determine mortar type, mix design, structural reinforcement or code compliance.
Related tools: Brick Calculator · Bricks per Square Foot · Retaining Wall Calculator · Exterior & Masonry Calculators.
Mortar coverage should come from the actual masonry system
Bag yield changes with brick or block dimensions, joint width and depth, unit absorption, waste and workmanship. A published “units per bag” value is therefore more useful than a generic assumption copied from another product.
Start with a reliable masonry-unit count, then enter the coverage stated for the mortar product and joint conditions you are using. Keep reinforcement, grout, flashing and other wall-system materials outside this bag calculation because they follow different quantity rules.
Example: bag yield changes mortar quantity
Consider a project with 1,000 masonry units and a chosen 5% extra-material allowance. That gives a planning basis of 1,050 units. If a compatible mortar product and joint configuration yields 80 units per bag, ceiling(1,050 ÷ 80) requires 14 bags. If a different hypothetical product or compatible configuration yields 100 units per bag, ceiling(1,050 ÷ 100) requires 11 bags.
These coverage values are made-up math examples, not manufacturer claims. Mortar type, joint size, unit absorption and mixing requirements determine the actual yield, and not every product will be suitable for the same wall. Always choose the mortar system from the project specification before comparing bags and prices.