Overview
This calculator gives a planning estimate for grout quantity on tiled floors and walls. It uses the tiled area, tile dimensions, joint width, joint depth, grout density, waste allowance, and the pack weight you plan to buy. The result helps you decide how many kilograms to prepare and how many bags to purchase before work starts. It is useful when tile formats change, joints are wider than usual, or you want to avoid stopping mid-job because the material ran out. For the best reading, enter values that match the actual tile and joint you will install. Very uneven substrates, large bevels, and decorative spacers can increase real consumption beyond the estimate.
Use cases
- Bathroom floor shopping listWork out the grout quantity for a compact bathroom floor with porcelain tiles and narrow joints.
- Large-format wall claddingEstimate how much grout is needed for oversized wall tiles where joint fill is shallow but surface area is high.
- Renovation top-up orderCheck the amount needed when you are finishing a small repair and want to buy the right pack size.
- Comparing joint layoutsSee how changing joint width or tile size affects total grout consumption before finalizing the layout.
How it works
- 1
Enter the total tiled area in square meters.
- 2
Add tile width and height in centimeters.
- 3
Set the joint width and joint depth in millimeters.
- 4
Choose grout density, waste percentage, and bag weight.
- 5
Read the estimated grout amount in kilograms and bags.
Examples
Bathroom floor with standard joints
Input: Area 12 m2, tile 30x60 cm, joint 2 mm, depth 8 mm, waste 10%, bag 5 kg
Output: Estimated grout requirement in kg plus the number of 5 kg bags to buy.
A realistic floor layout for a small bathroom using mid-size porcelain tiles.
Kitchen backsplash with small tiles
Input: Area 7.5 m2, tile 10x10 cm, joint 3 mm, depth 6 mm, waste 8%, bag 2 kg
Output: Estimated grout usage and rounded bag count for a backsplash order.
Small-format tiles create more joint volume, so the result is higher per square meter.
Hallway repair with wider joints
Input: Area 4.2 m2, tile 20x20 cm, joint 4 mm, depth 10 mm, waste 12%, bag 1 kg
Output: Estimated kilograms of grout and the number of 1 kg packs required.
Useful when replacing a section of floor and buying only the amount needed for the repair.
FAQ
Why do tile size and joint width change the result so much?
Smaller tiles and wider joints create more joint length and more space to fill, so the required grout rises quickly.
What does joint depth mean in this calculator?
It is the filled depth of the joint below the tile surface. Deeper joints need more grout because the cavity is larger.
Should I enter the room size or only the tiled area?
Enter only the area that will actually be tiled. Excluding uncut edges, openings, and non-tiled sections gives a more useful estimate.
Why does the bag count round up?
The tool rounds up because you cannot buy a fraction of a bag. If the result is close to the next bag, keep a small reserve for cuts and losses.
Can decorative or uneven tiles affect the estimate?
Yes. Ribbed backs, bevels, and uneven edges can change how much grout is pushed into the joints, so the real use may be higher.