Work out mortar quantity instantly with clear inputs, formula shown and shareable results.
Mortar occupies the joints, typically 15-25 percent of the masonry volume depending on unit size and joint thickness. Wet mortar volume is multiplied by 1.33 to allow for the bulking and void filling of dry sand, and the dry volume is split by the mix parts, with cement converted to bags at 1440 kg/m³.
Mortar volume
Wet m³ = wall area x thickness x mortar share
Materials
Dry = wet x 1.33; cement m³ = dry / (1 + sand parts); bags = cement m³ x 1440 / 50
Wet m³ = wall area x thickness x mortar share. Mortar occupies the joints, typically 15-25 percent of the masonry volume depending on unit size and joint thickness.
1:6 suits general internal brickwork, 1:5 external walls and 1:4 load-bearing or exposed work. A stronger mortar than the units themselves causes cracking through the bricks rather than the joints.
This calculator takes 4 inputs: Wall area, Wall thickness, Mortar mix, Mortar share of masonry volume. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.