Convert parts per billion to parts per million
1 ppb = 0.001 ppm
1 ppb = 0.001 ppm
1 ppb in every concentration unit
| part per trillion | 1,000 ppt |
| nanogram per liter | 1,000 ng/L |
| parts per billion | 1 ppb |
| microgram per liter | 1 μg/L |
| parts per million | 0.001 ppm |
| part per million by volume | 0.001 ppmv |
| milligram per kilogram | 0.001 mg/kg |
| milligram per liter | 0.001 mg/L |
| grain per US gallon (as CaCO₃) | 0.000058418 gpg |
| part per thousand | 0.000001 ppth |
| gram per liter | 0.000001 g/L |
| percent | 1.0000e-07 % |
| percent by weight | 1.0000e-07 % w/w |
| percent by volume | 1.0000e-07 % v/v |
| percent weight per volume | 1.0000e-07 % w/v |
| fraction (0–1) | 1.0000e-09 fraction |
How the conversion works
Multiply by 0.001 to go from parts per billion to parts per million, or divide by it to go back. Every conversion on this site routes through the SI value (%) rather than a table of pairwise factors, so a round-trip returns exactly what you started with.
Going the other way? parts per million to parts per billion — 1 ppm = 1,000 ppb.
parts per billion to parts per million — common values
| 1 ppb | 0.001 ppm |
| 2 ppb | 0.002 ppm |
| 3 ppb | 0.003 ppm |
| 5 ppb | 0.005 ppm |
| 10 ppb | 0.01 ppm |
| 15 ppb | 0.015 ppm |
| 20 ppb | 0.02 ppm |
| 25 ppb | 0.025 ppm |
| 50 ppb | 0.05 ppm |
| 75 ppb | 0.075 ppm |
| 100 ppb | 0.1 ppm |
| 250 ppb | 0.25 ppm |
| 500 ppb | 0.5 ppm |
| 1000 ppb | 1 ppm |