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Water Hardness Level by City, Town & Region in England

Choose your region of England to find the water hardness for your city, town and postcode. Every value comes from the water quality reports or database published by the water supplier for the area, in gpg, mg/l, Clark, German and French degrees.

Map of the nine regions of England

Five Units of Water Hardness

Water hardness is measured in several units, depending on the country and the product. Different appliance manuals and softener brands use different hardness units, so every chart gives you all of them side by side.

mg/l
Milligrams per litre
The unit used by water suppliers across the UK and Ireland.
gpg
Grains per gallon
The standard for sizing water softeners, based on the US gallon.
°Clark
Clark degrees
The traditional British unit, also called English degrees.
°dH
German degrees
Found on many dishwashers, coffee machines and test strips.
°fH
French degrees
Common across Europe and on many appliances sold in the UK.