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PPM Converter
Convert between ppm, percent, and mg/L.
Dilute concentrations, converted
Parts per million is the standard way to express tiny concentrations — a pollutant in water, a trace element in a sample. Converting between ppm, percent, and mg/L is a routine lab task.
A concentration of 250 ppm is 0.025 percent, and roughly 250 mg/L in dilute water. Pick your units and the tool converts through a common ppm base.
Handy and private
The conversion runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
What is ppm?
Parts per million — one part in a million, used for very dilute concentrations like water contaminants.
How does it relate to percent?
One percent equals 10,000 ppm. The tool converts between them.
What about mg/L?
For dilute water solutions, 1 ppm is approximately 1 milligram per litre.
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