CalcCalcolatore di Fughe
Ultimo aggiornamento: 2026-05-07
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| Area totale piastrellata (m2) | Lunghezza piastrella (cm) | Larghezza piastrella (cm) | Spessore piastrella (mm) | Larghezza fuga (mm) | |
|---|---|---|---|---|---|
| Small patio | 10 m2 | 15 cm | 30 cm | 8 mm | 3 mm |
| Medium patio | 15 m2 | 22.5 cm | 30 cm | 8 mm | 3 mm |
| Large patio | 20 m2 | 30 cm | 30 cm | 8 mm | 3 mm |
| Driveway | 30 m2 | 45 cm | 30 cm | 8 mm | 3 mm |
| Parking lot | 40 m2 | 60 cm | 30 cm | 8 mm | 3 mm |
What is the Grout Calculator?
Running out of grout mid-job means stopping to buy more — and the new batch may not match perfectly. The grout calculation formula accounts for tile size, joint width, tile thickness, and grout density to give you an accurate weight of grout powder needed in kilograms, ready to take to the hardware store.
You may also find the Backsplash Tile Calculator, Laminate Flooring Calculator, and Paver Calculator useful.
Who Uses This Calculator?
This tool is used by tilers, DIY homeowners, and tile contractors calculating material quantities.
How to Use the Grout Calculator
- Enter your Tile length.
- Enter your Tile width.
- Enter your Total tiled area.
- Enter your Grout joint width.
- Enter your Tile thickness.
- Click Calculate to see your results instantly.
Formula
The calculator uses the following formula:
Grout per m² = 2 × (L+W) ÷ (L×W) × grout_width × tile_thickness × grout_density
Worked Example
A 20 m² floor of 30 × 30 cm tiles with 3 mm joints and 8 mm tile thickness requires approximately 4.2 kg of grout powder.
Step-by-Step Calculation
- Joint length per m²: 2 × (30+30) ÷ (30×30) = 0.133 linear m per cm² → 1.33 m/m²
- Joint cross-section: 3 mm × 8 mm = 24 mm²
- Volume per m²: 1.33 × 0.024 = 0.032 litres ≈ 0.058 kg/m² for 20 m² = 1.16 kg
- Standard grout ≈ 1.7 kg/m² for 30×30 tile — total for 20 m² = 34 kg → 7 × 5 kg bags
Common Mistakes to Avoid
- Using tile dimensions in metres instead of centimetres
- Buying the same amount as tiles — grout quantity depends on joint width, not tile count
- Forgetting that unsanded grout is used for joints under 3 mm, sanded for wider joints
Frequently Asked Questions
The formula is: Grout (kg/m²) = 2 × (tile_L + tile_W) / (tile_L × tile_W) × joint_width × tile_thickness × grout_density. It accounts for the total joint volume per square metre.
Cement-based grout powder has a density of approximately 1.6–1.7 kg/litre. Epoxy grout systems vary — check the product data sheet. The calculator uses 1.6 as default.
Yes — cement grout is porous and will stain without sealing. Apply a penetrating grout sealer 24–48 hours after installation. Re-seal annually in high-traffic or wet areas. Epoxy grout does not need sealing.
Wait at least 24 hours after tiling (48 hours for large format tiles) to allow the adhesive to cure. Walking on tiles before the adhesive is set can cause tiles to shift and joints to open up.
No — mixing grout colours creates an inconsistent look and different batches of the same colour can vary. Buy all the grout you need from the same production batch.