UK Water Hardness Checker

Enter your postcode to see how hard your water is — and which type of filter actually makes sense for it. Covers 114+ UK postcode areas.

This is an estimate based on the main water supplier for your postcode area, using published water-company data. Supply zones don't map exactly to postcodes, so for your precise figure check your water company's website or your bill. Hardness is not a health risk — see is my tap water safe.