Chemistry Calculators
Formula in, numbers out. Molar mass from any chemical formula, mole and molarity conversions, dilutions and gas laws — using current standard atomic weights.
16 calculators
Most used
- Molar Mass (Molecular Weight)Enter a chemical formula — brackets, hydrates and ions included — and get its molar mass with an atom-by-atom breakdown and mass percentages.
- pH CalculatorFind pH, pOH, [H⁺] and [OH⁻] from any one value, or from the concentration of a strong acid, strong base, weak acid or weak base.
Moles & solutions 8
- Buffer pH (Henderson–Hasselbalch)Calculate the pH of a buffer with the Henderson–Hasselbalch equation, test it against added acid or base, or design a buffer for the pH you need.
- Dilution (C₁V₁ = C₂V₂)Find the stock volume, final volume or either concentration in a dilution, plus how much diluent to add and the dilution factor.
- Grams to MolesConvert grams to moles, moles to grams, or find a molar mass from both, with the number of particles from the Avogadro constant.
- Molar Mass (Molecular Weight)Enter a chemical formula — brackets, hydrates and ions included — and get its molar mass with an atom-by-atom breakdown and mass percentages.
- Molarity CalculatorWork out the mass of solute to weigh for a solution of known molarity and volume, or solve for the concentration or the volume instead.
- Percent Composition CalculatorFind the mass percent of every element in a formula, or work backward from percentages to the empirical and molecular formula.
- pH CalculatorFind pH, pOH, [H⁺] and [OH⁻] from any one value, or from the concentration of a strong acid, strong base, weak acid or weak base.
- Solution Concentration (ppm, %, M)Express one solution concentration in every common unit at once — molarity, molality, mass and volume percent, ppm, ppb and mole fraction.
Reactions & stoichiometry 4
- Empirical FormulaTurn percent composition, element masses or CO₂ and H₂O masses from combustion into the simplest whole-number formula and the molecular formula.
- Limiting ReactantEnter a reaction and the reactant amounts to see which one runs out first, how much product forms and how much of each excess reactant is left.
- Percent YieldCompare what a reaction actually produced with what it could have produced, or find the actual or theoretical yield from a known percentage.
- TitrationWork out an acid or base concentration from a titration, or the titrant volume needed, and see the pH curve with the equivalence point marked.
Gas laws & nuclear 4
- Boyle's Law (P₁V₁ = P₂V₂)Find how a gas's volume changes when you squeeze it, or how its pressure changes when it expands, at constant temperature.
- Charles's Law (V₁/T₁ = V₂/T₂)Find how much a gas expands when heated or shrinks when cooled at constant pressure, or the temperature that produces a given volume.
- Combined Gas Law (P₁V₁/T₁ = P₂V₂/T₂)Find how a fixed amount of gas responds when pressure, volume and temperature all change, solving for whichever of the six values is missing.
- Half-Life (Radioactive Decay)Work out remaining amount, original amount, age or half-life for radioactive decay, with isotope presets, a decay curve and a half-life table.
Guides
- How to Calculate Molar Mass From a Chemical FormulaAdd up the atomic weights of every atom in the formula. Worked examples with parentheses and hydrates, plus grams-to-moles and percent composition.
- How to Calculate Molarity and Make a Solution of Known ConcentrationMolarity is moles of solute per liter of solution. Step-by-step examples for calculating it, weighing out a solution, diluting stock and converting units.
- How to Calculate pH (Strong Acids, Bases, Weak Acids and Buffers)pH is the negative log of the hydrogen ion concentration. Step-by-step examples for strong and weak acids, bases and buffers, plus the logs behind the scale.