Molarity Calculator — Calculate Molarity, Moles & Volume (M = mol/L)M = mol/L · mol = M×V · V = mol/M · mmol · mM · μM · Dilution
Use this free Molarity Calculator to instantly solve any unknown variable in the fundamental molarity equation: M = mol / L — where M is the molar concentration in mol/L (Molarity), mol is the number of moles of solute, and L is the volume of solution in litres. Enter any two known values to automatically solve the third — computing: Molarity (M = mol / L) · Moles of solute (mol = M × V) · Solution volume (V = mol / M) — across all standard concentration units: mol/L (M) · mmol/L (mM) · μmol/L (μM) · nmol/L (nM) — with automatic unit conversion and molar mass-based mass-to-moles conversion (n = mass / molar mass).
This online molarity calculator is trusted across all areas of chemistry education and laboratory practice: A-Level, AP Chemistry, IB Chemistry, JEE, and NEET solution chemistry problems, university analytical and physical chemistry coursework, laboratory solution preparation — preparing standard solutions and working solutions from solid reagents, serial dilution and C₁V₁ = C₂V₂ dilution calculations, pharmaceutical drug concentration and compounding calculations, buffer preparation and titration solution standardization, and biochemistry — enzyme, protein, and DNA concentration calculations. Understanding molarity — the most widely used measure of solution concentration in chemistry — is fundamental to stoichiometry, titration, colligative properties, electrochemistry, and virtually every quantitative chemistry calculation. Trusted by chemistry students, laboratory technicians, pharmacists, biochemists, and research scientists worldwide.
Molarity Calculator — Concentration in Moles Per Liter for Solution Chemistry
Molarity (M) is moles of solute per liter of solution — the standard concentration unit in solution chemistry. Preparing a 0.5 M NaCl solution requires dissolving 0.5 moles × 58.44 g/mol = 29.22 grams of NaCl in enough water to make 1 liter of solution total. The molarity calculator converts between mass, moles, volume, and molar mass for any solute, handling the most common laboratory preparation task: making a solution of specified concentration from a solid or concentrated stock.
Serial dilution is the technique for preparing low-concentration solutions from high-concentration stocks. C₁V₁ = C₂V₂ is the dilution equation — if you want 100 mL of 0.01 M HCl from a 1 M stock, you need V₁ = (0.01 × 100)/1 = 1 mL of stock diluted to 100 mL total. For very low concentrations (10⁻⁶ M and below), multiple dilution steps are more practical than a single large dilution. The calculator chains multiple dilution steps and tracks the concentration at each stage.
Molality (moles per kg of solvent) differs from molarity (moles per liter of solution) and the distinction matters when temperature affects solution volume. A 1 M aqueous solution at 20°C has slightly different molality than the same solution at 80°C because the water expands with temperature, changing the volume but not the mass. Colligative properties — boiling point elevation, freezing point depression, osmotic pressure — are calculated from molality, not molarity. The calculator computes both and clarifies which concentration unit each application requires.