Water hardness by postcode in the United Kingdom

Enter your postcode: we match it to the nearest city with published hardness data and show its value, unit and source.

How the search works

Every postcode is matched to the nearest of the 471 cities in the United Kingdom for which a water supplier or regulator publishes hardness. Supply areas do not follow postcode boundaries, so the result is the figure of the nearest published supply. If the match is more than 15 km away we say so, and the annual water quality report of your own supplier is the better reference. Each city page names the source document and its date and, where the supplier publishes them, the values of each supply zone.

UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).

Regions

• Arun4 · 283 mg/L
• Barnsley11 · 227 mg/L
• Basingstoke and Deane3 · 303 mg/L
• Bradford16 · 54 mg/L
• Calderdale9 · 38 mg/L
• Doncaster11 · 269 mg/L
• Dorset27 · 296 mg/L
• Dover5 · 317 mg/L
• East Riding of Yorkshire22 · 288 mg/L
• Eastleigh7 · 300 mg/L
• Gravesham4 · 320 mg/L
• Hambleton3 · 248 mg/L
• Harrogate4 · 67 mg/L
• Horsham13 · 169 mg/L
• Isle of Wight14 · 268 mg/L
• Kirklees13 · 79 mg/L
• Leeds13 · 134 mg/L
• Medway6 · 223 mg/L
• New Forest5 · 282 mg/L
• Northern Ireland110 · 100 mg/L
• Richmondshire5 · 270 mg/L
• Rotherham9 · 242 mg/L
• Ryedale3 · 305 mg/L
• Scarborough5 · 204 mg/L
• Scotland24 · 31 mg/L
• Sedgemoor4 · 77 mg/L
• Selby4 · 286 mg/L
• Somerset West and Taunton6 · 48 mg/L
• South Somerset12 · 234 mg/L
• Swale9 · 303 mg/L
• Test Valley4 · 303 mg/L
• Thanet3 · 332 mg/L
• Wakefield12 · 276 mg/L
• Wiltshire34 · 304 mg/L
• Winchester5 · 302 mg/L
• York5 · 260 mg/L

Largest cities in the United Kingdom

All cities in the United Kingdom →