44 free calculators
Chemistry Tools
Every calculator runs in your browser, shows its working step by step, and needs no sign-up or install. Filter by level to find the tools for your class or your job.
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Units & measurement 3
- Chemistry Unit ConverterMass, volume, temperature, pressure, energy, density and more — every unit side by side.Middle schoolHigh schoolUniversityIndustry & lab
- Density CalculatorDensity, mass or volume in any units, with presets for common materials.Middle schoolHigh schoolIndustry & lab
- Significant Figures CalculatorCount sig figs, round to any number of them, and do sig-fig-correct arithmetic.Middle schoolHigh schoolUniversity
Elements & electrons 4
- Protons, Neutrons & Electrons CalculatorSubatomic particles for any element, isotope or ion, with its nuclide symbol.Middle schoolHigh school
- Electron Configuration GeneratorFull and noble-gas notation, with an orbital box diagram, for any element.High schoolUniversity
- Compare ElementsPut 2-4 elements side by side across every property, with a shareable link.Middle schoolHigh school
- Average Atomic Mass CalculatorWeighted average atomic mass from isotope masses and abundances, with real isotope presets.High schoolUniversity
Formulas & moles 5
- Molar Mass CalculatorParses any formula — parentheses, hydrates, all of it — into a full per-element mass breakdown.High schoolUniversityIndustry & lab
- Grams to Moles ConverterGrams ↔ moles ↔ particles for any formula, with the molar mass and each step shown.High schoolUniversity
- Percent Composition CalculatorMass percent of each element in a compound, and grams of each in any sample.High schoolUniversity
- Empirical Formula CalculatorEmpirical and molecular formulas from percent composition or grams, step by step.High schoolUniversity
- Oxidation Number CalculatorOxidation numbers for every element in a compound or ion, with the rule behind each.High schoolUniversity
Reactions & yield 5
- Chemical Equation BalancerBalances equations automatically and shows the coefficients step by step.Middle schoolHigh schoolUniversity
- Stoichiometry CalculatorGrams or moles of any reactant → amounts of every other substance, auto-balanced.High schoolUniversityIndustry & lab
- Limiting Reagent CalculatorLimiting reagent, theoretical yield, leftover excess and percent yield — auto-balanced.High schoolUniversityIndustry & lab
- Percent Yield CalculatorPercent yield, actual yield or theoretical yield in any mass unit.Middle schoolHigh schoolIndustry & lab
- Atom Economy CalculatorHow much of the reactants' mass ends up in the product you want — green chemistry in one number.High schoolUniversityIndustry & lab
Solutions, gases & pH 12
- Molarity & Dilution CalculatorMolarity, grams of solute needed, solution volume, and C₁V₁ = C₂V₂ dilutions.High schoolUniversityIndustry & lab
- pH CalculatorpH, pOH, [H⁺] and [OH⁻], plus strong and weak acid/base solutions.High schoolUniversityIndustry & lab
- Titration CalculatorUnknown concentration or volume from a titration, for any acid–base mole ratio.High schoolUniversityIndustry & lab
- Ideal Gas Law CalculatorSolve PV = nRT or the combined gas law in any mix of units.High schoolUniversityIndustry & lab
- Concentration ConverterMolarity, molality, % w/w, % w/v, ppm, mg/L and mole fraction from one value.High schoolUniversityIndustry & lab
- Buffer Calculator (Henderson–Hasselbalch)Buffer pH, pKa or the acid/base ratio you need, with common buffer presets.High schoolUniversityIndustry & lab
- Colligative Properties CalculatorBoiling-point elevation, freezing-point depression and osmotic pressure.University
- Serial Dilution CalculatorA full dilution series: concentration, transfer and diluent volumes at every step.UniversityIndustry & lab
- Solution Mixing CalculatorMix two solutions of different strength — final concentration or volumes needed.High schoolIndustry & lab
- Partial Pressure Calculator (Dalton's Law)Partial pressures and mole fractions for every gas in a mixture.High schoolUniversityIndustry & lab
- Graham's Law CalculatorRelative rates of effusion or diffusion, or an unknown gas's molar mass.High schoolUniversity
- Van der Waals Real Gas CalculatorReal-gas pressure from the van der Waals equation, compared with the ideal gas law.UniversityIndustry & lab
Energy & thermodynamics 4
- Specific Heat Calculator (q = mcΔT)Heat, mass, specific heat or temperature change, with material presets.Middle schoolHigh schoolIndustry & lab
- Bond Enthalpy CalculatorEstimate ΔH from bonds broken and formed using average bond enthalpies.High schoolUniversity
- Enthalpy of Reaction CalculatorΔH°rxn from standard enthalpies of formation (Hess's law), auto-balanced.High schoolUniversityIndustry & lab
- Gibbs Free Energy CalculatorΔG = ΔH − TΔS, spontaneity, crossover temperature and K from ΔG°.University
Rates & equilibrium 3
- Arrhenius Equation CalculatorActivation energy, rate constants or temperatures from the two-point Arrhenius equation.UniversityIndustry & lab
- Integrated Rate Law CalculatorZero-, first- and second-order kinetics: concentration over time and half-life.University
- Equilibrium (ICE Table) CalculatorEquilibrium concentrations from K and starting amounts, with the full ICE table.High schoolUniversity
Electrochemistry 2
Light & spectroscopy 2
Nuclear 1
Industry & environment 3
- Water Hardness CalculatorHardness as mg/L CaCO₃, °dH, °f and grains per gallon from calcium and magnesium.Industry & labUniversity
- Combustion & Air–Fuel Ratio CalculatorBalanced combustion, oxygen and air needed, and CO₂ produced per kilogram of fuel.High schoolUniversityIndustry & lab
- ppm to mg/m³ ConverterConvert gas concentrations between ppm and mg/m³ at any temperature and pressure.Industry & labUniversity