Soft or hard?
Hardness converter
Convert °dH, °fH, °e, mmol/l and ppm into one another and read off the hardness range and descaling interval.
1 °dH equals 0.1783 mmol/l, 1.78 °fH, 1.25 °e and 17.8 ppm calcium carbonate. The soft, medium and hard ranges follow the German Detergents Act (Waschmittelgesetz). Background in the article Understanding water hardness, and the values for your city under Regions.
