|Degree German hardness
|Degree of English hardness
|mval per liter
|Millimoles per liter
|Parts per million
|French degree hardness
The water hardness indicates how much calcium and magnesium are in the water. Further information on water hardness can be found on our information pages. To express the amount of calcium and magnesium, ie the water hardness in numbers, there are different units.
The hardness is an arbitrary division into three hardness ranges from soft to hard.
The most common unit in Germany is ° dH (degree German hardness). In other countries is measured with English or French degrees of hardness. Physically, the unit mmol / l (millimoles per liter) is the correct unit. Analogous to mmol / l, the unit mval / l is an obsolete unit that is hardly used anymore.
The unit ppm is an American unit. It indicates how many particles per million particles are contained. This statement is therefore like a percentage only per hundred, but per million.
To use the calculator, please enter your initial value and select the unit. Then you can carry out the conversion by clicking on the "calculate" button.