Water hardness in Maebashi
42 mg/L soft
Tap water in Maebashi is soft: 42 mg/L (2.5 gpg · 2.4 °dH · 4.2 °fH).
Source: Maebashi City Waterworks Bureau, tap-water quality results FY2026 (令和8年4・6・7月 水質検査結果 給水栓) (2026) · data checked 2026-10-21
Range across supply zones: 15–136 mg/L.
Maebashi's tap water is supplied by Maebashi City Waterworks Bureau; the intake mix is not confirmed here, but piped water in Gunma Prefecture comes mainly from rivers and reservoirs fed by short, steep catchments. The utility's 2026 data give 42.0 mg/L CaCO₃ within a range of 15.0 to 136.0 mg/L; the spread is wide, so the value at your tap depends on where in the supply area you live. Limescale is mild here, appearing slowly on kettles and taps, so occasional descaling is enough.
Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
Water data
| Total hardness | 42 mg/L |
|---|---|
| Utility | Maebashi City Waterworks Bureau |
How Maebashi compares
- Tap water in Maebashi is 16 % softer than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 150 of 228 in Japan (1 = hardest); 30 % of these cities have softer water.
- In Gunma it is number 10 of 11 cities; the regional median is 51 mg/L.
- Nearest city with clearly softer water: Kofu, 94 km away (18 mg/L).
- Nearest city with clearly harder water: Oizumi, 33 km away (62 mg/L).
Ranking of the hardest and softest water in Japan →
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 Maebashi
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 2 °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 Maebashi water hard or soft?
It is soft: 42 mg/L as CaCO₃ (2.5 gpg, 2.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Maebashi safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
How many grains per gallon is Maebashi water?
2.5 gpg, equal to 2.4 °dH, 4.2 °fH or 42 mg/L calcium carbonate.
What dishwasher salt setting should I use in Maebashi?
For 42 mg/L (2.4 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Maebashi?
No. With soft water a softener adds nothing.
Source
Source: Maebashi City Waterworks Bureau, tap-water quality results FY2026 (令和8年4・6・7月 水質検査結果 給水栓) (2026). Method: figure published by the water supplier. Maebashi City Waterworks Bureau, tap-water quality results FY2026 (令和8年4・6・7月 水質検査結果 給水栓) · Outdated figure? Tell us