Water hardness in Helsinki
3 °dH soft
Tap water in Helsinki is soft: 3 °dH (54 mg/L · 3.1 gpg · 5.4 °fH).
Source: HSY, Keskimääräinen vedenlaatu Pitkäkosken, Vanhankaupungin ja Kuninkaanlähteen vedenpuhdistuslaitoksilla 1.1.-15.6.2026 (2026-06) · data checked 2026-10-21
Range across supply zones: 54–73 mg/L.
Helsinki's figure comes from HSY, which publishes one table for its three plants (Pitkäkoski, Vanhankaupunki, Kuninkaanlähde) and the whole capital region. The plants read 3.0, 3.0 and 4.1 °dH for 1 January to 15 June 2026, so the page shows the median and that range. The PDF does not say which plant serves which street. Water at this level is soft, and limescale in kettles and heaters is slow to form.
Finnish waterworks report hardness in °dH; most supplies are soft.
Water data
| Total hardness | 3 °dH |
|---|---|
| Utility | HSY Helsingin seudun ympäristöpalvelut (Vesihuolto) |
How Helsinki compares
- Tap water in Helsinki is 13 % softer than the median of the 76 cities we track in Finland (3.5 °dH).
- By hardness it ranks 48 of 76 in Finland (1 = hardest); 33 % of these cities have softer water.
- Nearest city with clearly softer water: Hollola, 97 km away (1.8 °dH).
- Nearest city with clearly harder water: Klaukkala, 26 km away (4.9 °dH).
Ranking of the hardest and softest water in Finland →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Helsinki
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Helsinki water hard or soft?
It is soft: 54 mg/L as CaCO₃ (3.1 gpg, 3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Helsinki safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Finnish waterworks report hardness in °dH; most supplies are soft.
How many grains per gallon is Helsinki water?
3.1 gpg, equal to 3 °dH, 5.4 °fH or 54 mg/L calcium carbonate.
What dishwasher salt setting should I use in Helsinki?
For 54 mg/L (3 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Helsinki?
No. With soft water a softener adds nothing.
Source
Source: HSY, Keskimääräinen vedenlaatu Pitkäkosken, Vanhankaupungin ja Kuninkaanlähteen vedenpuhdistuslaitoksilla 1.1.-15.6.2026 (2026-06). Method: computed from supplier's calcium and magnesium. HSY, Keskimääräinen vedenlaatu Pitkäkosken, Vanhankaupungin ja Kuninkaanlähteen vedenpuhdistuslaitoksilla 1.1.-15.6.2026 · Outdated figure? Tell us