Convert a dKH carbonate-hardness or alkalinity reading to CaCO₃-equivalent mg/L, or to the conventional ppm reporting value for water near 1 kg/L. The reverse conversion is also available.
- All Unit Converters
- ug/ml to ppb Converter
- ppb to ng/ml Converter
- mg/l to g/mol Converter
- mg/l to pounds Converter
dKH to ppm Formula
The following formula is used to convert carbonate hardness from dKH into ppm or mg/L as CaCO₃.
For the reverse conversion, divide ppm by 17.86 to get dKH.
Variables:
- ppm is the CaCO₃-equivalent reporting value (numerically approximated by mg/L for water near 1 kg/L)
- dKH is the carbonate hardness in degrees KH
- 17.86 is the conversion factor from dKH to ppm
Multiply dKH by the conventional rounded factor 17.86 to get mg/L as CaCO₃. Reporting the same number as ppm assumes water density near 1 kg/L; this conversion does not adjust for salinity or temperature.
What is dKH to ppm Conversion?
dKH is a German degree used for carbonate hardness and, by aquarium test-kit convention, alkalinity. Results as CaCO₃ describe an equivalent reporting basis, not the actual calcium concentration. Alkalinity and total hardness remain distinct measurements; compare readings only when the test-kit parameter and basis match.
One degree of carbonate hardness is equal to approximately 17.86 ppm as CaCO₃. That means the conversion is direct and uses a constant multiplier, making it easy to switch between units.
How to Convert dKH to ppm?
The following steps outline how to convert dKH to ppm.
- First, determine the carbonate hardness value in dKH.
- Next, use the conversion factor 17.86.
- Multiply the dKH value by 17.86 to calculate ppm as CaCO₃.
- The same numeric reporting value is used for ppm and mg/L as CaCO₃ under the near-1-kg/L water-density assumption.
- Check your answer using the calculator above.
Example Problem:
Use the following variable as an example problem to test your knowledge.
Carbonate Hardness (dKH) = 8
ppm (as CaCO₃) = 8 × 17.86 = 142.88 ppm
dKH to ppm Conversion Table
The table below shows common dKH values converted into ppm as CaCO₃ using the formula ppm = dKH × 17.86.
| Carbonate Hardness (dKH) | ppm (as CaCO₃) |
|---|---|
| 1 dKH | 17.86 ppm |
| 2 dKH | 35.72 ppm |
| 4 dKH | 71.44 ppm |
| 6 dKH | 107.16 ppm |
| 8 dKH | 142.88 ppm |
| 10 dKH | 178.60 ppm |
| 12 dKH | 214.32 ppm |
This conversion is commonly used in aquarium care, municipal water testing, and chemistry references. Since the relationship is fixed, converting between dKH and ppm is simple and helps standardize measurements across different sources.
