Repointing Mortar Calculator

Inputs

Enter wall, joint, and mix details

Use consistent units. Choose metric or imperial first.

Fields arranged 3 columns (large), 2 (medium), 1 (mobile).

Unit system

Switching units changes labels; inputs are not auto-converted.

Wall input mode

Use area mode when the wall is irregular.

Wall length

m

Wall height

m

Openings (optional)

Add windows/doors to deduct from repointing area.

Up to 3 opening types

Opening 1 width

m

Opening 1 height

m

Opening 1 quantity

Opening 2 width

m

Opening 2 height

m

Opening 2 quantity

Opening 3 width

m

Opening 3 height

m

Opening 3 quantity

Masonry details

Brick size and joint thickness affect joint length per area.

Brick length

mm

Brick height

mm

Joint thickness (bed & perp)

mm

Repointing parameters

Repointing depth is the raked-out depth filled with new mortar.

Joint width to fill

mm

Repointing depth

mm

Joint profile factor

Waste / loss allowance

%

Typical: 8–15%. Increase for difficult access.

Dry volume factor

Default 1.33 converts wet mortar to dry ingredients volume.

Include vertical joints

Uncheck for bed-joint-only repointing.

Materials & mix

Ratios are by volume parts (Cement : Lime : Sand).

Mix preset

Cement parts

Lime parts

Sand parts

Cement bag size

Material estimates use typical bulk densities.

Optional labor estimate

Use your crew’s known productivity for a realistic schedule.

Productivity

m² / person-day

Crew size

Example

Example input and output

Use this as a quick reference for typical settings.

Parameter	Example value	Notes
Wall area (net)	10.0 m²	After deducting 1.2 m² openings
Brick size	215 × 65 mm	Common modular brick size
Joint thickness / width	10 mm	Bed and perp joints
Repointing depth	15 mm	Typical raked-out depth
Mix ratio (C:L:S)	1 : 1 : 6	General repointing mortar
Waste allowance	10%	Adjust for access and tooling
Estimated wet mortar	~0.030–0.050 m³	Varies with joint geometry and profile

Formula

Formula used in this calculator

1) Net repointing area

If you enter wall length and height:

Wall Area = Length × Height
Net Area = Wall Area − Σ(Openings Width × Height × Quantity)

Area mode uses your entered total area, then subtracts openings.

2) Joint length per 1 m² (approx.)

Courses per meter = 1 / (Brick Height + Joint Thickness)
Bricks per meter (in a course) = 1 / (Brick Length + Joint Thickness)

Horizontal Joint Length = Courses per meter × 1.0 m
Vertical Joint Length = Courses per meter × Bricks per meter × Brick Height

This is a stretcher-bond approximation. For stone or irregular work, increase waste or adjust dimensions.

3) Mortar volume

Wet Volume per m² = (Total Joint Length) × (Joint Width) × (Repoint Depth) × (Profile Factor)
Total Wet Volume = Wet Volume per m² × Net Area × (1 + Waste%)

4) Ingredient split (dry)

Dry Volume = Total Wet Volume × Dry Factor
Cement Volume = Dry Volume × (Cement Parts / Total Parts)
Lime Volume = Dry Volume × (Lime Parts / Total Parts)
Sand Volume = Dry Volume × (Sand Parts / Total Parts)

Guide

How to use this repointing mortar calculator

Select your unit system first, then enter all values in those units.
Enter wall geometry using length × height or total area for irregular walls.
Deduct openings for windows, doors, and large vents to avoid over-ordering.
Set joint width and repointing depth based on a real site measurement.
Choose a mix ratio or enter a custom ratio to match specifications.
Adjust waste and profile factor for tooling style and access constraints.
Calculate, review the result block, and download CSV/PDF for records.

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