How to test your water hardness
The fastest way to know your water hardness is to look it up, since most municipalities publish their figure. For your own tap, a test strip gives a number in minutes, a soap-shake test gives a rough read for free, and a lab gives the exact number. A private well should always be tested directly.
- Check your municipal figure first. Look up your city's published hardness; it is free and official. Use the Almanac's by-municipality figures or your utility's annual water-quality report.
- Use a test strip for your own tap. Hold a hardness test strip under the cold tap, then match the colour to the chart. It reads in grains per gallon or mg/L within a minute and matters most on a well, or where the city figure varies by neighbourhood.
- Try the soap-shake test for a free rough read. Half-fill a clear bottle with tap water, add a few drops of pure liquid soap, and shake. Plenty of fluffy lather means soft water; thin lather with cloudy water means hard.
- Send a sample to a lab for the exact number. For a precise figure, especially before buying or sizing a softener, a certified lab or your provincial drinking-water program will test a sample.
What the numbers mean
Results come in milligrams per litre as calcium carbonate (mg/L) or grains per gallon (gpg), and one grain is about 17.1 mg/L. Under 60 mg/L is soft, 60 to 130 is moderately hard, 130 to 180 is hard, and over 180 is very hard. A softener is set in grains, so note that unit if you plan to buy one.
When to test your own tap instead of trusting the city figure
Test your own tap if you are on a private well, if your city draws from groundwater that varies by neighbourhood, or before you size a softener. The municipal figure is a good starting point, but the number at your street is what a softener has to be set to.
Testing water hardness, in brief
What is a normal water hardness level?
There is no single normal. Under 60 mg/L is soft, 60 to 130 moderately hard, 130 to 180 hard, and over 180 very hard. Many Ontario groundwater cities run well above 180.
How accurate are water hardness test strips?
Strips are accurate enough to choose and size a softener. For an exact figure, use a certified lab.
Where can I test my water for free?
Your municipal water-quality report is free and lists the figure. The soap-shake test is a free rough check at home; some utilities also provide test kits.
Sources
Hardness bands and units follow Health Canada drinking-water operational parameters. Municipal figures are each city's own published values, last checked 2026-06-24.
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