Free calculatorWorks with My Project

Grout Calculator

Estimate grout from tile size, joint width and project area.

My ProjectNo saved space selectedSave a room once and reuse it here.

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Your estimate

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Enter the tiled area, tile dimensions and joint size to estimate grout quantity, bags and optional cost.

Plan with confidence

How to use the Grout Calculator

Estimate grout weight and full bags using the tile dimensions, joint dimensions and project area instead of relying on a single generic coverage rate.

Step by step

What to enter

Enter the tiled area or reuse a saved room.
Enter tile length and width. If you previously saved a Tile calculation for the same room, PlanCalq can reuse those dimensions.
Enter grout-joint width, joint depth and the density value appropriate to your grout.
Choose waste, bag size and an optional price per bag.

Method

How the calculation works

The grout consumption rate increases as joints become wider or deeper and decreases as tile dimensions become larger.

PlanCalq calculates an estimated grout weight per unit area from tile perimeter, joint dimensions and density, multiplies that by the project area, adds waste and rounds up to full bags.

Calculation summary

Consumption rate ≈ ((tile length + tile width) × joint width × joint depth × density) ÷ (tile length × tile width)

Project area × consumption rate = estimated grout weightRecommended weight ÷ bag size = bags to buy (rounded up)

Worked example

Example: why grout changes with joint size

Floor area: 20 m²
Tile: 600 mm × 600 mm
Joint width: 3 mm
Joint depth: 8 mm

Planning resultA large tile with a narrow joint uses far less grout per square metre than a small tile with the same joint width.

Grout quantity depends on the total length of joints across the tiled area. Larger tiles create fewer joint lines, while wider or deeper joints increase the cross-sectional volume that must be filled. PlanCalq uses those dimensions together rather than relying on floor area alone.

Interpret the output

How to read the result

Treat the calculated weight as a planning requirement and round it to the bag sizes sold by your chosen grout manufacturer.
If your actual joint width changes during installation, recalculate because grout consumption can move materially.
Use the product label density or coverage guidance when it differs from the assumptions in the calculator.

Planning limits

What this calculator does not cover

Irregular stone, varying joint depths and heavily textured tile edges can increase consumption.
The tool does not determine grout type, colour, movement-joint design or suitability for wet areas.
Manufacturer coverage tables remain the final reference for a specific grout product.

PlanCalq methodology & safety boundaries →

GuideTile and flooring waste

Understand why tile and flooring projects need extra material, what increases waste, and how pack rounding differs from a waste allowance.

GuideInterpreting calculator estimates

Learn the difference between theoretical quantity, recommended quantity, purchase quantity and estimated cost so you can use calculator results responsibly.

Common questions