Percent to Parts per Billion Converter
Common Conversions
| % | ppb |
|---|---|
| 1e-7 | 1 |
| 0.000001 | 10 |
| 0.00001 | 100 |
| 0.0001 | 1000 |
| 0.001 | 10000 |
| 0.01 | 100000 |
| 0.1 | 1000000 |
| 1 | 10000000 |
| 10 | 100000000 |
| 100 | 1000000000 |
| 1000 | 10000000000 |
| 10000 | 100000000000 |
Why this conversion matters in chemistry
A reagent listed as 99.9% pure has 0.1% — that is, 10⁶ ppb — of something that isn't the labeled compound. The factor between percent and ppb is 10⁷, which is also the factor between bulk purity and the trace-impurity scale that pharmaceutical-grade and semiconductor-grade specifications care about. A 99.999% ("5 nines") high-purity material carries 10 ppm of impurity, which is 10,000 ppb. The conversion comes up most when an assay percentage on a certificate of analysis has to land alongside a trace-metal impurity table on the same document, or when an ICH Q3D elemental-impurity limit is expressed in ppb but the reagent assay is in percent.
Formula
Worked Examples
One percent — ten million parts per billion. The conversion anchor and a useful reminder of how the scales relate.
Equivalently 1 ppm — the trace-impurity range a high-purity reagent specification might quote.
100 ppm of impurity — at the upper end of what's typical for an analytical-grade reagent.
10 ppm — a working spec for many ACS-grade reagents and a common target in pharmacopeial impurity tables.