Science
Chemistry Calculators
Moles, molarity, dilution, pH, gas laws, stoichiometry and more. Free calculators with formulas and worked examples.
Moles and mass
Molar Mass Calculator (Molecular Weight from Formula)Type a chemical formula to get its molar mass and percent composition.Grams to Moles Calculator (and Moles to Grams)Enter a formula and a mass or amount to convert between grams and moles.Percent Composition Calculator (Mass Percent)Enter a formula and an element to get its mass percent and how much is in your sample.
Solutions
Molality CalculatorEnter solute mass, molar mass and solvent mass to get the molality.Mole Fraction CalculatorEnter the moles of each component to get mole fractions.Normality CalculatorConvert molarity to normality, or find normality from mass and volume.Boiling Point Elevation CalculatorEnter molality, the van 't Hoff factor and the solvent to get the boiling point elevation.Freezing Point Depression CalculatorEnter molality, the van 't Hoff factor and the solvent to get the freezing point depression.Osmotic Pressure Calculator (π = iMRT)Enter molarity, the van 't Hoff factor and temperature to get osmotic pressure.Concentration Converter (Molarity, g/L, % w/v, ppm)Enter a concentration and molar mass to see it in every common unit.Molarity CalculatorFind molarity and moles from a mass of solute dissolved in a volume.Dilution Calculator (C1V1 = C2V2)How much stock solution do you need to make a diluted solution?pH CalculatorEnter a pH or concentration and get the other acid-base values.PPM and Concentration ConverterConvert a concentration between common units for water-like solutions.Buffer pH Calculator (Henderson–Hasselbalch)Find the pH of an acetate, phosphate or other buffer.
Gas laws
Boyle's Law Calculator (P₁V₁ = P₂V₂)Enter the known values and choose what to solve for.Charles's Law Calculator (V₁/T₁ = V₂/T₂)Enter the known values and choose what to solve for.Gay-Lussac's Law Calculator (P₁/T₁ = P₂/T₂)Enter the known values and choose what to solve for.Combined Gas Law Calculator (P₁V₁/T₁ = P₂V₂/T₂)Enter the known values and choose what to solve for.Van der Waals Equation Calculator (Real Gas Pressure)Pick a gas, enter moles, volume and temperature to compare real and ideal gas pressure.
Kinetics and thermodynamics
Arrhenius Equation Calculator (Rate Constant and Activation Energy)Find how a reaction rate changes with temperature, or the activation energy from two measurements.Gibbs Free Energy Calculator (ΔG = ΔH − TΔS)Enter ΔH, ΔS and temperature to see if a reaction is spontaneous and its equilibrium constant.Calorimetry Calculator (Heat and Enthalpy of Reaction)Enter the solution mass, specific heat and temperature change to get q and ΔH.Bond Enthalpy Calculator (ΔH from Bond Energies)List the bond energies broken and formed to estimate the reaction enthalpy.
Electrochemistry
Analytical chemistry
Stoichiometry
Theoretical Yield CalculatorEnter the limiting reactant, the mole ratio and molar masses to get the maximum product mass.Limiting Reagent CalculatorEnter two reactants and the balanced equation coefficients to find which one runs out first.Atom Economy Calculator (Green Chemistry)Enter the molar mass of the desired product and of all reactants to get the atom economy.Moles CalculatorConvert grams to moles and molecules.Percent Yield CalculatorHow efficient was your reaction?Titration CalculatorWork out an unknown concentration from a titration result.
Acids and bases
About these calculators
Chemistry calculations for students and labs: moles and molar mass, concentration and dilution, pH and buffers, stoichiometry, gas laws, reaction rates and thermochemistry. Each calculator shows the formula, units and a worked example.
Each calculator explains its formula, includes a worked example and lists its sources. Read how we check them on our editorial policy page, or browse all calculators.
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