WaterHow Hard Is Your Water?
Check water hardness for any UK postcode. See your area's PPM level, what it means for your home, and how to fix it.
Covering 2,289 postcode districts across the UK
2,289
Postcodes Covered
15
Water Companies
205 ppm
UK Average
Hard
Average Classification
Top 10 Hardest Water Areas in the UK
| # | Postcode | Town | Water Company | Hardness | Level |
|---|---|---|---|---|---|
| 1 | CM19 | Harlow | Anglian Water | | Very Hard |
| 2 | CM18 | Harlow | Anglian Water | | Very Hard |
| 3 | IP33 | Bury St Edmunds | Anglian Water | | Very Hard |
| 4 | CM17 | Harlow | Anglian Water | | Very Hard |
| 5 | IP32 | Bury St Edmunds | Anglian Water | | Very Hard |
| 6 | NR19 | Dereham | Anglian Water | | Very Hard |
| 7 | CM16 | Epping | Anglian Water | | Very Hard |
| 8 | IP31 | Bury St Edmunds | Anglian Water | | Very Hard |
| 9 | NR18 | Wymondham | Anglian Water | | Very Hard |
| 10 | CM15 | Brentwood | Anglian Water | | Very Hard |
Top 10 Softest Water Areas in the UK
| # | Postcode | Town | Water Company | Hardness | Level |
|---|---|---|---|---|---|
| 1 | SY11 | Oswestry | Welsh Water (Dwr Cymru) | | Soft |
| 2 | SY12 | Ellesmere | Welsh Water (Dwr Cymru) | | Soft |
| 3 | SY13 | Whitchurch | Welsh Water (Dwr Cymru) | | Soft |
| 4 | SY14 | Malpas | Welsh Water (Dwr Cymru) | | Soft |
| 5 | SY15 | Montgomery | Welsh Water (Dwr Cymru) | | Soft |
| 6 | SY16 | Newtown | Welsh Water (Dwr Cymru) | | Soft |
| 7 | SY17 | Caersws | Welsh Water (Dwr Cymru) | | Soft |
| 8 | TA10 | Langport | South West Water | | Soft |
| 9 | SY18 | Llanidloes | Welsh Water (Dwr Cymru) | | Soft |
| 10 | TQ10 | South Brent | South West Water | | Soft |
UK Water Companies
Anglian Water
Avg: 321 ppm Very Hard
261 postcodes
Thames Water
Avg: 302 ppm Very Hard
354 postcodes
South East Water
Avg: 297 ppm Hard
17 postcodes
Affinity Water
Avg: 268 ppm Hard
33 postcodes
Southern Water
Avg: 263 ppm Hard
131 postcodes
Portsmouth Water
Avg: 261 ppm Hard
34 postcodes
SES Water
Avg: 239 ppm Hard
7 postcodes
Wessex Water
Avg: 231 ppm Hard
123 postcodes
Severn Trent Water
Avg: 221 ppm Hard
401 postcodes
Yorkshire Water
Avg: 215 ppm Hard
218 postcodes
Northumbrian Water
Avg: 101 ppm Slightly Hard
122 postcodes
South West Water
Avg: 80 ppm Slightly Hard
129 postcodes
United Utilities
Avg: 77 ppm Slightly Hard
242 postcodes
Welsh Water (Dwr Cymru)
Avg: 68 ppm Slightly Hard
214 postcodes
Scottish Water
Avg: 54 ppm Soft
3 postcodes
Water Hardness Guides
What Is Water Hardness?
Understanding PPM, calcium carbonate, and why it matters for your home.
Hard Water Effects
How hard water impacts your skin, hair, appliances, and energy bills.
Hard Water Solutions
Water softeners, filters, and other ways to deal with hard water.
Water Softener Guide
Types of water softeners, how they work, costs, and our top picks.
Get Water Hardness Updates
Be notified when your water company reports changes to hardness levels.