part per million to per mille converter

Convert part per million to per mille in the Ratios and concentrations family. See a sample calculation, unit definitions, and the interactive converter.

Example conversion: 1 ppm

0.001 per mille

This example is calculated from the same unit registry used by the interactive converter.

Formula and unit definitions

Convert decimal fractions, percentages, ppm and other dimensionless ratio formats.

target value = source value × source factor ÷ target factor

Source unit: part per million (ppm), factor 1e-06, offset 0.

Target unit: per mille (permille), factor 0.001, offset 0.

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Important note

The calculation is performed locally from the listed unit definitions. Display results are rounded for readability; high-precision and regulated work should use the governing standard and appropriate significant figures.

For high-precision, regulated or safety-critical use, check the underlying standard and its required precision. Historical and approximate units are identified in their names or family descriptions.

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