Water hardness in Toronto
119 mg/L moderately hard
Tap water in Toronto is moderately hard: 119 mg/L (7 gpg · 6.7 °dH · 11.9 °fH).
Source: City of Toronto, Drinking Water Analysis Summary 2025 (2025) · data checked 2026-10-20
Range across supply zones: 115–122 mg/L.
The City of Toronto publishes one citywide figure for its drinking water system. Its 2025 summary gives an average of 119 mg/L as calculated CaCO3, with annual readings between 115 and 122 mg/L. There are no separate hardness zones to check. Expect some scale on kettles and water heaters.
Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
Water data
| Total hardness | 119 mg/L |
|---|---|
| Utility | City of Toronto (Toronto Water) |
How Toronto compares
- Tap water in Toronto is 18 % harder than the median of the 254 cities we track in Canada (101 mg/L).
- By hardness it ranks 113 of 254 in Canada (1 = hardest); 55 % of these cities have softer water.
- In Ontario it is number 74 of 120 cities; the regional median is 124 mg/L.
- Nearest city with clearly softer water: Collingwood, 108 km away (86 mg/L).
- Nearest city with clearly harder water: Stouffville, 31 km away (318 mg/L).
Ranking of the hardest and softest water in Canada →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Toronto
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Toronto water hard or soft?
It is moderately hard: 119 mg/L as CaCO₃ (7 gpg, 6.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Toronto safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
How many grains per gallon is Toronto water?
7 gpg, equal to 6.7 °dH, 11.9 °fH or 119 mg/L calcium carbonate.
What dishwasher salt setting should I use in Toronto?
For 119 mg/L (6.7 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Toronto?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: City of Toronto, Drinking Water Analysis Summary 2025 (2025). Method: figure published by the water supplier. City of Toronto, Drinking Water Analysis Summary 2025 · Outdated figure? Tell us