Parts per Million and Parts per Billion Calculator
Expresses a very small concentration as parts per million or billion.
Parts per million
— ppm
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Parts per billion — ppb
Percent — %
Reading this —
The formula
ppm = part ÷ whole × 1,000,000 ppb = part ÷ whole × 1,000,000,000
Both are the same ratio on different scales, so 1 ppm is 1,000 ppb.
What to watch out for
The whole includes the substance itself, though at these levels the difference is usually too small to matter.
Frequently Asked Questions
How many ppb are in 1 ppm?
1,000.
What is 5 mg in 1 kg in ppm?
5 ppm, which is 5,000 ppb.
How do I convert ppm to percent?
Divide by 10,000. 5 ppm is 5.000 × 10⁻⁴%.