Parts Per Converter
Fast, accurate parts Per conversions, right in your browser.
The Parts Per Converter converts between parts-per-million (ppm), parts-per-billion (ppb), and percentage — commonly used in chemistry, water quality testing, and environmental science where concentrations are too small to express conveniently as a percentage.
How to Convert
- Enter your value and select the starting unit
- Choose your target unit
- The converted result appears instantly
Frequently Asked Questions
What does "parts per" mean in this converter?
It refers to concentration units like percent, parts per million (ppm), and parts per billion (ppb), used to express very small proportions or concentrations.
How is percent related to ppm?
1% equals 10,000 ppm — percent is parts-per-hundred, while ppm is parts-per-million, so converting between them involves a factor of 10,000.
Where are ppm and ppb commonly used?
Chemistry, environmental science, and water quality testing frequently use ppm and ppb to express trace concentrations of substances, like contaminants or dissolved minerals.
What is the difference between ppm and ppb?
Ppm (parts per million) and ppb (parts per billion) both measure concentration, but ppb is a thousand times smaller — 1 ppm equals 1,000 ppb.
Is this tool free to use?
Yes, completely free with no signup, no limits and no software to install.
Is my data saved anywhere?
No — conversions run in your browser and the values you enter are not stored or sent to a server.
Is this useful for lab or scientific work?
Yes — converting between concentration units is a routine task in chemistry, environmental testing, and pharmaceutical work.
How do I convert ppm to a decimal fraction?
Divide the ppm value by 1,000,000. For example, 500 ppm = 0.0005 as a decimal fraction.
Does this support parts per trillion (ppt)?
Yes, extremely dilute concentration units like ppt are typically included for specialized scientific use cases.
Can this be used for financial basis points?
Basis points (1/100th of a percent) follow a similar proportional logic, though this tool is primarily designed for scientific concentration units — check whether basis points are included in the unit list.
