EVERYDAY
Ratios & concentration
Dimensionless ratios, percentages and parts-per notation.
Try a decimal, 1e-9, 1/3, or 5 1/2.
Resultppm → 1Convert parts per million to ratio
EVERYDAY · ENGINEERING · SCIENCE
Unit conversion. Made clear.
Start with a familiar unit, type a value, and get a dependable answer with sensible precision. Fractions and scientific notation are welcome.
520units ready to convert
HOW IT IS CALCULATED
Convert through ratio
Enter a parts per million value to calculate ratio with full internal precision before display rounding.
Display precisionAuto · 12 significant digits
Auto keeps up to 12 significant digits, trims unnecessary zeroes, and switches to scientific notation for extreme magnitudes.
QUICK REFERENCE
All units in this quantity
| Unit | Symbol | Converted value |
|---|---|---|
| ratiofrom ppm | 1 | Interactive |
| percentfrom ppm | % | Interactive |
| per millefrom ppm | ‰ | Interactive |
| parts per millionfrom ppm | ppm | Interactive |
| parts per billionfrom ppm | ppb | Interactive |
| parts per trillionfrom ppm | ppt | Interactive |
SI symbols follow international notation. U.S. and Imperial measures are labelled separately where their values differ.