Authoritative definitions of the International System of Units and SI prefixes.
Unit conversion
Per mille to Fraction Converter
1 ‰ = 0.001 fraction. Enter a value to convert ‰ to Fraction, then use the formula and table below. Displayed digits may be rounded.
Chemistry concentration unitsInstant result
Decimals
Formula result = input × 0.001 ÷ 1. 1 ‰ = 0.001
Nonzero results too small for the selected decimal places use scientific notation.
Nonzero results too small for the selected decimal places use scientific notation.
Common examples
One value, several units
Fraction0.001
Percent0.1 %
Parts per million1,000 ppm
Parts per billion1,000,000 ppb
Conversion table
| ‰ | |
|---|---|
| 1 ‰ | 0.001 |
| 2 ‰ | 0.002 |
| 5 ‰ | 0.005 |
| 10 ‰ | 0.01 |
| 25 ‰ | 0.025 |
| 50 ‰ | 0.05 |
| 100 ‰ | 0.1 |
Conversion chart
1 ‰0.001
5 ‰0.005
10 ‰0.01
25 ‰0.025
50 ‰0.05
Worked example
1 ‰ = 0.001 Fraction. Apply the selected conversion formula to other input values.
Unit definition
Per mille (‰) One per mille equals 0.001 fraction.
Unit history
Per mille is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert ‰ to fraction.
3. Convert the base value to and apply your display precision.
Important
Mass/volume ppm equivalence depends on solution density.
Understand the result before using it
Per mille to Fraction converts a value measured in Per mille (‰) into the equivalent value in Fraction (). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 0.001 ÷ 1
Assumptions
- Per mille and Fraction represent the same dilute-solution parts quantity.
- The input is expressed in ‰; the output is expressed in fraction.
- Mass/volume ppm equivalence depends on solution density.
Worked example
1 ‰ = 0.001 fraction. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a ‰ measurement in a document that expects fraction.
- Compare a per mille value with a value reported in fraction.
- Check the ‰ to fraction arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- A ppm value is not automatically a mass-per-volume value; the equivalence depends on density and how concentration is defined.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Per mille to Fraction?
result = input × 0.001 ÷ 1. Input is in ‰; result is in fraction. 1 ‰ = 0.001 fraction. The displayed digits may be rounded.
What is 1 ‰ in fraction?
1 ‰ = 0.001 fraction. The displayed digits may be rounded.
Can I reverse the ‰ to fraction conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts fraction back to ‰.
Is the Per mille to Fraction result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.