Water hardness in Paris
26.1 °fH very hard
Tap water in Paris is very hard: 26.1 °fH (261 mg/L · 15.2 gpg · 14.6 °dH).
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 75056 (2026-06) · data checked 2026-10-19
Range across supply zones: 255–290 mg/L.
Eau de Paris draws about half of its water from the Seine and the Marne, treated at the Orly and Joinville plants, and the rest from springs captured far from the city in the Paris Basin. This water moves through chalk and limestone, which explains a hardness of 261.0 mg/L CaCO₃, between 255.0 and 290.0 mg/L depending on the sector. Kettles and washing machines need regular descaling.
TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
Water data
| Total hardness | 26.1 °fH |
|---|---|
| Utility | Eau De Paris |
How Paris compares
- Tap water in Paris is 9 % harder than the median of the 33641 cities we track in France (23.9 °fH).
- By hardness it ranks 14048 of 33641 in France (1 = hardest); 58 % of these cities have softer water.
- Nearest city with clearly softer water: Neuilly-sur-Seine, 6 km away (17.8 °fH).
- Nearest city with clearly harder water: Le Blanc-Mesnil, 12 km away (36.7 °fH).
Ranking of the hardest and softest water in France →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Paris
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Paris water hard or soft?
It is very hard: 261 mg/L as CaCO₃ (15.2 gpg, 14.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Paris safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
How many grains per gallon is Paris water?
15.2 gpg, equal to 14.6 °dH, 26.1 °fH or 261 mg/L calcium carbonate.
What dishwasher salt setting should I use in Paris?
For 261 mg/L (14.6 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Paris?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 75056 (2026-06). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 75056 · Outdated figure? Tell us