Setting out
Whole tiles across and cut tile size on a run (from one end)
- where
- whole tiles across
- run length (mm)
- edge gap at each end (mm)
- tile size along the run (mm)
- joint width (mm)
- cut tile at the far end (mm)
Explain this equation
Works out how many whole tiles fit along a run when you start with a whole tile at one end, and the size of the cut at the other end.
L is the run length, e any edge gap at each end, t the tile size along the run and j the joint. n is the number of whole tiles and c the cut at the far end.
Each whole tile uses its size plus one joint, so dividing the available length by t + j and rounding down gives the whole tiles. What remains is the cut, which sits against the wall or gap so it has no joint after it.
Sense check: 2.45 m of 300 mm tiles with 2 mm joints takes eight whole tiles and a 34 mm cut, which is a sliver worth avoiding by balancing.
Watch out: small cuts at a visible end look poor; use balanced cuts for visible runs.
Starting with a whole tile at one end, how many whole tiles fit and the size of the cut at the other end.
Enter your values to see the result.
Good to know
Each whole tile takes up its own size plus one joint; the last space is the cut (it sits against the wall or gap, so it has no joint after it). Useful for splashbacks against a worktop end, or where one end is hidden. For visible runs, balance the cuts instead.
Common mistake
Forgetting the joints: twelve 200 mm tiles with 3 mm joints run 36 mm longer than 2.4 m.
Limits
Straight runs. Subtract the thickness of trims or upstands from the run first.
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.