Mortar Calculator

This mortar calculator is a tool that will come handy during any wall construction project. Use it to calculate the number of mortar bags needed.

Leave at zero to use the dimensions above.
Extra to cover offcuts, breakage and mistakes.
Leave at zero to skip the costing.
Clear
Bricks needed1,1881,080 to cover it, plus 10% waste, rounded up
Exact requirement1,080 bricks
Each brick covers0.1481 sq ft0.01376 m²
Wall area after deductions160 sq ft14.8645 m²
Per square foot6.75 bricks
Nominal face size8 × 2.667 inunit plus one mortar joint
Actual unit size7.625 × 2.25 × 3.625 in
Mortar needed39.6 cu ftabout one cubic foot per 30 bricks
Bags of mortar mix6080 lb bags, 0.66 cu ft each

The method

units = wall area ÷ nominal face area, plus waste

Nominal size is what counts

A US modular brick measures 7⅝ × 2¼ inches, but you lay it on a ⅜-inch mortar joint, so it occupies an 8 × 2⅔ inch space in the wall. Divide a square foot by that and you get 6.75 bricks — which is why suppliers quote “about 7 per square foot”.

Concrete block works out even more neatly: a nominal 16 × 8 inch face is 128 square inches, so it is exactly 1.125 blocks per square foot.

The mortar figures are rules of thumb — roughly a cubic foot per 30 bricks or 12 blocks — and they vary with joint thickness and how much you waste on the board.