Water Hardness Calculator
Enter any two values to solve the third. You can also enter water hardness alone to convert and classify it.
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How this result is classified
USGS water hardness scale
- 0 to 60 mg/L as CaCO₃
- Soft Your result
- > 60 to 120 mg/L as CaCO₃
- Moderately hard Your result
- > 120 to 180 mg/L as CaCO₃
- Hard Your result
- > 180 mg/L as CaCO₃
- Very hard Your result
Source: USGS Hardness of Water
How it was calculated
Calculation
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Equivalent values
mg/L as CaCO₃
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ppm as CaCO₃
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Grains per gallon
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German degrees
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French degrees
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Hardness breakdown
Carbonate hardness
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Noncarbonate hardness
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