⚗️ Chemistry calculators

Molarity, stoichiometry, gas laws and solutions. 20 calculators.

• Arrhenius Equation CalculatorCalculate the reaction rate constant from activation energy, temperature and pre-exponential factor.
• Beer–Lambert Law Calculator (Absorbance)Calculate absorbance, concentration or molar absorptivity using A = εlc, plus transmittance.
• Boyle's Law Calculator (P₁V₁ = P₂V₂)Calculate new pressure or volume of a gas at constant temperature using Boyle's law.
• Buffer pH Calculator (Henderson–Hasselbalch)Calculate buffer pH from pKa and the concentrations of weak acid and conjugate base — or the ratio needed for a target pH.
• Charles's Law Calculator (V₁/T₁ = V₂/T₂)Calculate new volume or temperature of a gas at constant pressure using Charles's law.
• Combined Gas Law CalculatorSolve P₁V₁/T₁ = P₂V₂/T₂ for any unknown — pressure, volume or temperature of a fixed amount of gas.
• Dilution Calculator (C₁V₁ = C₂V₂)Calculate how much stock solution and solvent you need to make a diluted solution — or the final concentration.
• Gibbs Free Energy Calculator (ΔG = ΔH − TΔS)Calculate Gibbs free energy change to predict whether a reaction is spontaneous at a given temperature.
• Half-Life Calculator (Radioactive Decay)Calculate the amount remaining after radioactive decay — or the half-life or time elapsed.
• Mass Percent (w/w) Concentration CalculatorCalculate mass percent concentration of a solution from solute and solvent mass — or the solute needed for a target percent.
• Molality CalculatorCalculate molality (mol/kg) from the mass of solute, its molar mass and the mass of solvent.
• Molarity CalculatorCalculate molarity (mol/L), the mass of solute needed, or the solution volume for any substance.
• Moles Calculator (Mass ↔ Moles ↔ Particles)Convert between grams, moles and number of particles using molar mass and Avogadro's number.
• Osmotic Pressure CalculatorCalculate osmotic pressure from molarity, van 't Hoff factor and temperature using π = iMRT.
• Percent Composition CalculatorCalculate the mass percent of an element in a compound from atom count, atomic mass and molar mass.
• Percent Yield CalculatorCalculate the percent yield of a chemical reaction from the actual and theoretical yield.
• pH CalculatorConvert between pH, pOH, hydrogen ion and hydroxide ion concentration — with acidic or basic classification.
• PPM Calculator (Parts per Million)Calculate concentration in ppm from solute and solution mass — and convert ppm to percent and mg/L.
• Specific Heat Calculator (q = mcΔT)Calculate heat energy needed to change a substance's temperature — or the temperature change from added heat.
• Titration CalculatorCalculate the unknown concentration of an acid or base from titration volumes and the mole ratio.