Calculator
Example data table
| Area (m²) | Tile (mm) | Joint width (mm) | Joint depth (mm) | Density (kg/m³) | Waste (%) | Bag size (kg) | Estimated mass (kg) | Bags (rounded) |
|---|---|---|---|---|---|---|---|---|
| 12.000 | 300 × 300 | 3 | 8 | 1800 | 10 | 5 | ~8.10 | 2 |
| 25.000 | 600 × 600 | 2 | 6 | 1700 | 8 | 10 | ~4.59 | 1 |
Formula used
This calculator estimates grout volume per square meter from joint geometry and tile size, then converts volume to mass using grout density and adds waste.
How to use this calculator
- Choose units for tile and joint measurements.
- Select Direct area or Room mode for area input.
- Enter tile length and width, then joint width and depth.
- Set grout density from the product data sheet if available.
- Add a waste allowance and your preferred bag size.
- Press Calculate to view results, then download CSV or PDF.
Tile grout estimation guide
A grout take‑off links design details to procurement so installation stays continuous and finishes are consistent. This page calculates grout mass from joint volume, then rounds to whole bags for purchasing. Use it during planning, bidding, or site control to reduce overruns and minimize partial‑bag storage risks.
1) Coverage drivers you can control
Grout consumption depends on how much joint length exists per square meter and on the joint cross‑section. Smaller tiles increase joint length because there are more edges per area. Wider joints increase volume linearly, and deeper joints increase volume linearly as well. A change from 2 mm to 4 mm joint width typically doubles the required grout mass when tile size and depth remain the same. Consistent spacers and flat substrate help keep joint width uniform across the floor or wall.
2) Joint depth and profile assumptions
Joint depth is commonly close to tile thickness but may be reduced by setting-bed squeeze-out or by tooling style. For accurate results, aim for joints that are properly cleaned before grouting so the depth is available for packing. If you use a shallow joint profile for decorative work, reduce the depth input accordingly. On uneven surfaces, expect localized deeper joints that increase overall usage.
3) Density, product type, and mixing
The calculator converts joint volume to mass using grout density from the manufacturer data sheet. Cementitious grouts often fall around 1400–1800 kg/m³, while polymer‑modified and epoxy systems can vary. Keep mixing water within the stated range; extra water can weaken grout and change coverage due to shrinkage. Where color uniformity matters, keep batch size, mixing time, and cleaning method consistent.
4) Waste allowance and purchasing strategy
Add waste for textured tiles, porous edges, narrow joints that require rework, and frequent bucket changes. Complex layouts with many cuts, penetrations, or drains also increase loss. A practical field allowance is often 5–15%, depending on workmanship and tile type. Use the rounded bag count to plan deliveries and storage, and prefer purchasing from the same production batch when possible to reduce shade variation.
FAQs
1) What tile size should I enter for rectangular tiles?
Enter the actual length and width of one tile. The calculator uses both dimensions to estimate total joint length per square meter.
2) Should joint depth equal tile thickness?
Often it is close, but it can be reduced by adhesive squeeze-out or tooling. Use the depth you expect to be available after cleaning joints before grouting.
3) Where do I get grout density?
Check the product technical data sheet. If unavailable, use a typical value and validate by testing a small area to compare actual coverage.
4) How do I handle spacers and inconsistent joints?
Use the intended joint width as the input, then increase the waste percentage to cover real variation caused by uneven tiles, substrate deviations, or workmanship.
5) Does this work for wall tiles and vertical surfaces?
Yes. The estimate is based on area and joint geometry. For walls, consider extra waste for sag, cleanup, and stopping points at corners and trims.
6) Why does the calculator round up bags?
Grout is purchased in whole bags. Rounding helps avoid shortfalls that can delay installation and lead to color differences when a new batch is mixed later.
7) How accurate is the result?
It is a planning estimate. Accuracy improves when inputs match site conditions, joints are clean, and density comes from the data sheet. Always verify with a small trial area.