⚗️ Percent Purity Calculator
Work out how pure a chemical sample is by comparing the mass of the active substance to the total sample mass.
What percent purity tells you
Percent purity is the proportion of a sample that consists of the desired chemical compound rather than impurities, solvent residue, or byproducts. It is a standard way to report the quality of a synthesized or purchased chemical.
The formula used
Percent purity = (mass of pure substance ÷ total sample mass) × 100. If you also enter the molar mass of the pure substance, the calculator additionally reports the moles of active compound present, which is useful for planning reactions or dilutions.
- Mass of pure substance should come from an assay, titration, or certificate of analysis.
- Impurity mass is simply the difference between total mass and pure mass.
This tool is intended for general chemistry and laboratory planning purposes; always confirm purity figures against your certificate of analysis for regulated or safety-critical work.