Result
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Facts and limits of this method
| Formula | Percent = per mille × 0.1 |
|---|---|
| 1 per mille (‰) | 0.1 percent — one part per thousand |
| 1 percent (%) | 10 per mille — one part per hundred |
| Common uses | Blood alcohol concentration, water salinity, measurement instrument precision |
When it misleads you
- The 1 ‰ = 0.1 % ratio is an exact definition by the very meaning of the units (both express a fraction of a whole, differing only in scale), so the converter introduces no error of its own beyond the chosen rounding precision.
- Per mille is used more often where percent would give awkwardly small fractional numbers — blood alcohol concentration, for example, is usually measured in per mille (0.5 ‰) rather than percent (0.05 %), simply because that's more customary for the context.
- At "0 — whole number" precision, the fractional part of the result is dropped by rounding rules, not truncation.
- The input accepts both a period and a comma as a decimal separator.
How it is calculated
Per mille is one part per thousand of a whole (denoted ‰), percent is one part per hundred (denoted %). Since a thousandth is ten times smaller than a hundredth, converting per mille to percent is dividing by 10.
The entered value in per mille is multiplied by 0.1 (equivalent to dividing by 10) to get percent.
The reverse ratio — 10 per mille in one percent — is shown in a separate row to quickly check the conversion direction.
The calculation updates instantly on every change to the input field or precision.
Questions and answers
What is per mille in plain terms?
It's one part per thousand of a whole — like percent, only a unit ten times smaller for measuring the same kind of fraction.
Where is per mille most commonly used?
In medicine and law for blood alcohol concentration, in chemistry for water salinity, and in metrology for measurement instrument precision and tolerances.
Is 5 per mille a lot or a little?
5 ‰ equals 0.5 % — compare it against your task's context: for blood alcohol concentration that's a very high value, for instrument precision it's usually an acceptable amount.
Is my data sent anywhere?
No, the whole calculation runs in your browser.