FixMeasure
How it works
Grout quantity comes from the volume of the joints: joint length per m² is (tile length + width) ÷ (length × width), multiplied by joint width and depth. Grout density is taken as about 1.7 kg/L, so the result is an estimate.
You may also need: Tile, Waterproofing.
How to measure
Measure the tiled area; take tile size and thickness from the box. Joint width is the size of your tile spacers.
Worked example
Here is an example using the calculator’s default values:
Inputs
- Tiled area: 110 ft²
- Tile length: 12 in
- Tile width: 12 in
- Joint width: 0.125 in
- Joint depth (tile thickness): 0.313 in
- Waste allowance: 10%
Result
- Grout needed (estimate): 6.97 lb
- kg per m²: 0.3
- 10 lb bags: 1
Tips
- Use the manufacturer's coverage chart if there is one.
- Small tiles have far more joint length, so they need much more grout.
- Buy bags with the same batch number; color can vary between batches.
Common mistakes
- Guessing the joint width: a 5 mm joint needs more than twice the grout of a 2 mm joint.
- Forgetting tile thickness, which sets the joint depth.
- Mixing batches, so the grout color varies.
Frequently asked questions
How much grout do I need per square meter?
It depends on tile size and joint width; for 30 × 30 cm tiles with 3 mm joints, roughly 0.3 kg/m².
Why do small tiles need more grout?
They have much more joint length per square meter.
Sanded or unsanded grout?
Unsanded for narrow joints of about 3 mm or less, sanded for wider joints; follow the product's range.