Tile quantities
Mosaic sheets needed
- where
- sheets per m²
- sheet length and width (mm)
- joint between sheets (mm)
- sheets to order
- area to tile (m²)
- waste allowance (%)
Explain this equation
Works out how many mosaic sheets to buy for an area, allowing for the joint left between neighbouring sheets.
S1 and S2 are the sheet length and width and j is the joint between sheets. n is the number of sheets per square metre, and Ns the number to order for area A with waste w.
Each sheet plus one joint on two sides is the repeating block, so 1 000 000 mm² divided by that block area gives sheets per m². Adding waste and rounding up gives whole sheets.
Sense check: 300 × 300 mm sheets laid as a 300 mm module are 11.1 per m², so a 3.2 m² splashback with 10% waste needs 40 sheets.
Watch out: many sheets are made so that the sheet plus one joint is a round module. Lay a few dry to find the true pitch.
Number of mosaic sheets for an area, allowing for the joint left between sheets so the pattern reads continuously.
Enter your values to see the result.
Good to know
Many mosaic sheets are made so that sheet size plus one joint equals a neat module (e.g. 300 mm). Lay a few sheets dry to measure the true pitch, and enter that as the sheet size with a zero joint. Mosaics are cut by snipping the mesh, so waste is usually close to straight-lay figures unless the design is directional.
Common mistake
Butting sheets together without the matching joint, so the gap between sheets is visible as a grid.
Limits
Rectangular sheets only. Glass and natural stone mosaics may need more for colour selection.
Sources
Results are calculations from the published methods and manufacturer figures shown, and depend on the data you enter. Always follow the tile, adhesive and grout manufacturers’ instructions, BS 5385 and the Tile Association guidance. Coverage rates vary by product and substrate. Check prices and VAT rules with your own records and HMRC.