The concentration converter is a free online tool that helps you convert between chemistry units quickly and accurately. It supports 6 units including Molar (M), Millimolar (mM), Micromolar (μM), Parts per million (ppm), Parts per billion (ppb), Percent (%). The core conversion formula is: 1 M = 1000 mM = 1,000,000 μM. For example, 1 Molar equals approximately 1,000 Millimolar. Conversely, 1 Millimolar equals approximately 0.001 Molar. Common conversions: 5 M = 5,000 mM, 10 M = 10,000 mM, 25 M = 25,000 mM, 50 M = 50,000 mM, 100 M = 100,000 mM. This converter is useful for students, engineers, scientists, and professionals who need accurate chemistry unit conversions. Whether you are working on homework, technical specifications, research data, or everyday measurements, this tool provides instant, reliable results. All conversions are calculated relative to a single base unit for consistency and precision across all supported units. PPM is commonly used to measure pollutants in water. 1 ppm is equivalent to 1 milligram per liter in water.