PPM to percent, ppb to mg/L, g/L to ppm, plus mass and mole fraction—free and instant. For chemistry labs, environmental testing, and pharma. No sign-up required.
Scientific and technical measurements
International System of Units (SI) measurements
This free concentration converter supports ppm to percent, mass fraction, mole fraction, ppm, ppb, and more for chemistry labs, environmental testing, and pharmaceuticals. For molarity (mol/L, g/L) use our Molarity Converter; for salinity and TDS see the Salinity and TDS Converter; for acidity try our pH Converter.
Convert between molarity, mass concentration, and percentage solutions for chemical reactions and analysis.
Convert between ppm, ppb, and other concentration units for water quality, air pollution, and soil analysis.
Convert drug concentrations between different units for dosage calculations and formulation.
Unit fractions, percentages, and parts per million/billion/trillion for precise concentration measurements.
Mass per volume concentration units for solid and liquid solutions.
Moles per volume concentration units for chemical calculations.
Weight per volume concentration units for dense solutions.
Weight per weight concentration units for solid mixtures.
Our concentration converter uses unit fractions (0 to 1) as the base unit for all fraction-based conversions, ensuring accurate relationships between percentages, ppm, ppb, and ppt.
Mass and molar concentrations are converted using standard relationships and molecular weights for accurate chemical calculations.