Concrete Block Mortar Calculator

Estimate mortar for a concrete block or CMU wall by wall size or by a known block count. It includes joints, waste, bag count, cost, formula steps, and a printable report.

Measurement inputs

Live calculation updates the mortar estimate and the wall preview.

Live

Project name Used in the printable report.

Unit system Switches starter units only.

Estimate method Use block count if you already know it.

Concrete block size Thickness × height × length.

Wall length

Wall height

Openings area

Doors/windows to subtract.

Mortar joint thickness

Waste

Mortar bag yield Use the printed bag yield for final buying.

Cost per mortar bag Optional. Leave 0 if cost is not needed.

This uses a practical joint estimate: one bed joint and one head joint per block. Final mortar needs can change by block type, waste, workmanship, and bag yield.

Live 3D wall preview

The same SVG is used in the report so the shape does not change later.

Wall size–

Block size–

Blocks–

Joint–

Mortar needed with waste

–

Enter valid wall or block details to calculate.

Ready

Base mortar volume–

Mortar bags–

Estimated blocks–

Estimated cost–

Cubic feet–

Cubic yards–

Cubic meters–

Wall area–

Formula used

Mortar per block = Wall thickness × Joint thickness × (Block length + Block height)

All block and joint measurements are converted to inches before the mortar joint volume is calculated.

Calculation steps

Enter measurements to view the calculation steps.