Hard water map
Hard water is common across much of the UK, but exact results can vary from area to area. Use our hard water map below to check your local levels.
Hard water is common across much of the UK, but exact results can vary from area to area. Use our hard water map below to check your local levels.
Enter your postcode to see your home’s exact water hardness level, along with guidance on whether a water softener is recommended.
Milligrams of calcium carbonate in every litre of water
Water hardness zones shown are approximate.
For detailed, location-specific information, please enter your postcode.
At ppm (parts per million)
Your result
ppm
Water hardness index
Milligrams of calcium carbonate in every litre of water
is a area at ppm
Water hardness is measured by the number of mineral deposits in your water (parts per million – ppm). It’s these mineral deposits – including calcium and magnesium – that cause water to become hard.
A soft water area would have under 60ppm, while a very hard water area would register more than 300ppm.
Water hardness varies across the UK due to the types of rock that water passes through. In areas with chalk and limestone, like the South and East, water picks up more calcium and magnesium minerals, making it harder. In regions with granite or other, less soluble rocks – like much of Scotland and Wales – water remains softer.
If you’re unsure if your area has hard or soft water, enter your postcode in our hard water checker above.
To learn more about the science behind hard water, read our full guide exploring where hard water comes from and how it affects your home.
Discover our award-winning water softeners designed to eliminate limescale, protect your appliances, and improve overall water quality.
Curious how our water softeners remove the hardness minerals from your water? Find out more in our guide to ion exchange and its benefits.
