Mortar Calculator
Work out how much bricklaying mortar you need. Enter the area to cover and the calculator returns the quantity (allowing for waste) and an indicative cost.
How we estimate this
A 20kg bag of pre-mixed mortar lays roughly 25 to 30 standard bricks, about half a square metre of single-skin wall. Double-brick walls use roughly double, and bigger joints use more.
Pricing reviewed: October 2026.
Pricing reviewed October 2026. Indicative Australian costs, not a quote.
Understanding mortars in Australia
A 20kg bag of pre-mixed mortar lays roughly 25 to 30 standard bricks, about half a square metre of single-skin wall. Double-brick walls use roughly double, and bigger joints use more.
Mix mortar in small batches so it does not go off before it is used, and keep the mix consistent for a uniform colour across the wall.
Frequently asked questions
How much mortar do I need for bricklaying?
Roughly one 20kg bag per half a square metre of single-skin wall (about 25 to 30 bricks). Double brick uses roughly double.
How many bricks does a bag of mortar lay?
A 20kg bag of pre-mixed mortar lays roughly 25 to 30 standard bricks, depending on joint size.
Are you a supplier / trades business?
Everyone on this page is working out what mortar costs because they are ready to hire. Put your business right beneath the calculator, in your state, so you are who they find. From $50/mo.