About the Water Hardness Converter
Convert water hardness between mg/L (as CaCO3), ppm (as CaCO3), grains per gallon (gpg), and degrees German (°dH) or French (°fH). Enter a value above, choose the source and target units, then click Convert. All calculations run locally in your browser for speed and privacy.
Conversion factors used
- 1 gpg = 17.1 mg/L (as CaCO3)
- 1 °dH = 17.848 mg/L (as CaCO3)
- 1 °fH = 10 mg/L (as CaCO3)
- ppm ≈ mg/L (as CaCO3) for water
How to use
- Enter the numeric value you want to convert.
- Select the source unit (e.g., mg/L).
- Select the target unit (e.g., gpg).
- Press Convert to see the result below the form.