About the PPM Calculator
Convert between ppm, ppb, percent and mg/L, for water quality and trace concentrations.
Also known as: parts per million, ppb calculator, ppm to percent, mg/l to ppm, ppm conversion.
How to use this calculator
- Enter value is in, value, sample volume (optional).
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
1 ppm = 1 mg/L in water = 0.0001%
Worked example
Using the values pre-filled in the calculator above:
- Value is in: ppm
- Value = 250
- Sample volume (optional) = 1 L
the calculator returns:
- Parts per million: 250 ppm
- Parts per billion: 250,000
- Percent: 0.025 %
- mg/L (in water): 250