Brick quantity calculator

Bricks per square metre come from the brick face plus one joint each way, so 1 ÷ ((length + joint) × (height + joint)). The laid count is that rate over the net wall area times the leaf count, rounded up; the buy count rounds up again with wastage on top. Wet mortar is estimated as wall volume minus the bricks' own volume, which reads a little low because mortar outside the wall face and wedges cut for openings are ignored. Suppliers sell by the pack, so round the buy count up again to whole packs before ordering.