Paris
Paris, France has an estimated water hardness of 249 ppm (mg/L as calcium carbonate), which is classed as very hard. High scale risk. Configure appliances and descale regularly.
Paris water hardness in every unit
| Unit | Average |
|---|---|
| mg/L or ppm (CaCO₃) | 249 |
| mmol/L | 2.49 |
| German degrees (°dH) | 13.95 |
| French degrees (°fH) | 24.9 |
| Clark degrees (°e) | 17.47 |
| Grains per US gallon (gpg) | 14.55 |
Published range: 220–280 ppm.
Where Paris's water comes from
- Supplier: Eau de Paris (public water operator)
- Source: Roughly half from underground springs 80–150 km from Paris, and half from the Seine and Marne rivers
River water is treated at the Orly (Seine) and Joinville (Marne) plants. Eau de Paris: where does the water come from (checked 2026-10-05).
How Paris compares
With an average of 249 ppm, Paris ranks 3rd hardest of the 19 cities in our directory, 183 ppm above the directory median of 66 ppm. Among the cities in our directory in Europe, Berlin is the hardest at 303 ppm and Manchester is the softest at 25 ppm.
What the range means
Published figures for Paris run from 220 to 280 ppm. That is a wide spread (60 ppm), so the figure at your own tap could differ a lot from the average. Supply zones, blending of different water sources, and the time of year can all move it. A test strip or your utility's postcode lookup is worth the extra step here.
What very hard water means at home
Very hard water forms scale quickly on heating elements and in pipework, shortens the interval between descaling, and often leaves visible marks on glass and tiles. Appliance-level protection (salt, filters, scheduled descaling) is worth the effort, and some households consider a whole-home softener.
Appliance settings for 249 ppm water
- Dishwasher: salt yes; highest hardness band. Use dishwasher salt and verify the exact model setting in the manual.
- Coffee machine: descale every 4–6 weeks; filter: strongly recommended.
- Laundry: use the hard-water dose. Use the label maximum only for large or heavily soiled loads.
- Kettle: descale every 2–4 weeks.
- Humidifier: use demineralised or distilled water; clean every 3 days.
Frequently asked questions
How hard is the water in Paris?
The estimate for Paris, France is about 249 mg/L as calcium carbonate (13.95 °dH, 24.9 °fH, 14.55 gpg), with a published range of 220–280 mg/L. That is classed as very hard water. Citywide published estimate.
Do I need dishwasher salt in Paris?
Yes. Use dishwasher salt and verify the exact model setting in the manual. Always follow your dishwasher manual.
How often should I descale a coffee machine in Paris?
At this hardness, descale every 4–6 weeks. Water filter: strongly recommended.
Do I need a water softener in Paris?
It is worth considering. At this level scale builds quickly, so a softener or filter system can reduce descaling and protect appliances. Check your appliance manuals first, as some limit softened-water use.
Is hard water in Paris safe to drink?
Water hardness is mainly an aesthetic and scale issue. The World Health Organization does not set a health-based guideline value for it. Hardness affects taste, scale and detergent use rather than drinking safety, and your utility is responsible for meeting drinking-water standards. If you have a specific health or dietary concern, ask your doctor.
Who supplies tap water in Paris?
Eau de Paris (public water operator). Source: Roughly half from underground springs 80–150 km from Paris, and half from the Seine and Marne rivers.
How to check your own water
City averages are a starting point. To get your actual figure, look for the latest water-quality report from French public health water data or your local supplier, or dip a hardness test strip in a glass of cold tap water and read it against the chart. Strips usually report in °dH, gpg or ppm; enter the number into the Waterdial checker to convert it and see the matching appliance settings. A manual reading always beats a city estimate.
Source
French public health water data, checked 2026-10-05. Guidance is general; your appliance manual takes priority.
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