How this calculator works
A standard 70 lb bag of mortar lays roughly 125 bricks or 30 concrete blocks. The calculator divides your unit count by that rate and rounds up.
Worked example — 500 bricks:
500 ÷ 125 = 4 bags of mortar mix.
500 ÷ 125 = 4 bags of mortar mix.
Joint size changes it
Thicker mortar joints use more mix. These figures assume a standard 3/8-inch joint; wider joints or hollow blocks filled with mortar will need more.
Frequently asked questions
How many bricks does a bag of mortar lay?
About 125 bricks per 70 lb bag with a standard joint.
How much mortar for concrete block?
Roughly one bag per 30 blocks.