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Concentration

ppbtoppm

Convert parts per billion (10⁻⁹) (ppb) to parts per million (10⁻⁶) (ppm).

Factor1 ppb = 0.001 ppm

Converter

ppb

Accepts numbers or expressions, e.g. 150 + 14.7

Result
1ppm

Rendered to 6 significant figures.

Formula

Formula
ppm = ppb × 0.001

Multiply any value in parts per billion (10⁻⁹) by 0.001 to obtain the value in parts per million (10⁻⁶).

Worked example

Convert 1000 ppb to ppm.

  1. 01Start with 1000 ppb.
  2. 02Multiply by the conversion factor: 1000 × 0.001 = 1 ppm.
Result1000 ppb = 1 ppm

Conversion table

ppbppm
10.001
20.002
50.005
100.01
200.02
500.05
1000.1
2000.2
5000.5
10001

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from ppb to ppm?
1 ppb equals 0.001 ppm. To convert, multiply the value in parts per billion (10⁻⁹) by 0.001.
How do I convert 1 ppb to ppm?
1 ppb = 0.001 ppm. For any value, multiply by 0.001.
How do I convert ppm back to ppb?
Divide by the same factor — or equivalently, multiply by 1000. So 1 ppm = 1000 ppb.
When would I need to convert parts per billion (10⁻⁹) to parts per million (10⁻⁶)?
Concentration-ratio conversions between ppb and ppm are used in trace-analysis, gas-composition work, environmental reporting and process-chemistry datasheets. These conversions are dimensionless: they do NOT cover mg/L, g/L, mol/L, normality, equivalents, mass-percent, volume-percent, ppmw or ppmv — those require solution density and/or molecular weight. Note: ppt here means parts per trillion (10⁻¹²), not parts per thousand.
Is the conversion exact?
Yes. Both ppb and ppm are defined by exact SI relationships, so the displayed factor is exact (any rounding shown is only for display).

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