Hardness unit converter
Convert water hardness between mg/L as CaCO3, German degrees, French degrees, grains per gallon and meq/L, with a soft-to-very-hard classification.
Results
| mg/L as CaCO3 (ppm) | 120 |
|---|---|
| German degrees (°dH) | 6,72 |
| French degrees (°f) | 12 |
| Grains per US gallon (gpg) | 7,01 |
| meq/L | 2,398 |
At 120 mg/L as CaCO3 this water classifies as hard. Expect scale on heating elements, geysers and RO membranes — softening (or antiscalant dosing ahead of RO) is the standard response. Size a softener on measured hardness and real daily consumption, with a volumetric valve so regeneration follows actual use.
Formula used
1 °dH = 17.848 mg/L as CaCO3
1 °f = 10 mg/L as CaCO3
1 gpg (US) = 17.118 mg/L as CaCO3
1 meq/L = 50.045 mg/L as CaCO3
- °dH
- German degrees of hardness
- °f
- French degrees of hardness
- gpg
- grains per US gallon
- meq/L
- milliequivalents per litre
All conversions run through mg/L as CaCO3 as the common basis. Classification bands used: soft < 60, moderately hard 60–120, hard 120–180, very hard > 180 mg/L as CaCO3, following the WHO convention. Other sources place the boundaries a little differently, so treat a value near a boundary as being in both bands rather than as a decided classification.
Equipment for this duty
Send the water analysis and duty point, and the branch confirms exact selections, pricing and lead times — usually within one working day.
Request a quoteResults are indicative engineering estimates based on standard formulas and typical assumptions. They are not a design service; confirm any design against a full water analysis and the relevant manufacturer’s data.