Calculator
Drain size matcher
Three measurements decide which anti-odour core or valve will actually fit. Enter them and this tells you the type, the size, whether you need an adapter ring, and whether your depth is enough.
Fill in the three measurements and press Match my drain.
Measure three times
Grates are rarely perfectly round and recesses are rarely concentric. Take each measurement twice, at 90° to each other, and use the smaller number. If the two differ by more than 5 mm, the recess is out of round and a silicone part will not seal.
Common sizes
| Drain | Grate recess | Bore | Typical clear depth |
|---|---|---|---|
| Standard domestic floor drain | 100 mm | 50 mm | 70–110 mm |
| Shower tray waste | 90 mm | 40 mm | 45–70 mm |
| Deep seal floor drain | 110 mm | 50 mm | 120–160 mm |
| Linear channel | — | 40–50 mm | 60–90 mm |