Volume
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Masonry · step 3 of 3
Mortar calculator
How much mortar to lay your block, by block count — the final step after blocks and grout fill.
Mortar for the laying
FIG. 03required
Planning figure: about 16 blocks laid per cubic foot of mortar (~6 ft³ per 100 blocks). A standard 80-lb bag of mortar mix yields roughly 0.5 ft³.
How this is calculated
About one cubic foot of mortar per 16 blocks laid (roughly 6 cubic feet per 100 blocks). For a 190-block wall with a waste margin that's roughly 13 cubic feet, or around 26 standard 80-lb bags of mortar mix. Enter your block count above.
mortar ft³ = blocks ÷ 16 × (1 + waste%) · bags = ft³ ÷ 0.5
The last step of the block-wall workflow — start at the block wall calculator, then grout fill.
FAQ
How much mortar do I need for a block wall?
About one cubic foot of mortar per 16 blocks laid (roughly 6 cubic feet per 100 blocks). For a 190-block wall with a waste margin that's roughly 13 cubic feet, or around 26 standard 80-lb bags of mortar mix. Enter your block count above.
How many blocks does a bag of mortar lay?
A standard 80-lb bag of mortar mix yields about 0.5 cubic feet and lays roughly 8 blocks, so plan on about one bag per 8 blocks. Conditions and joint size change this, so add a waste margin.