Calculator directory
Chemistry Calculators
ChemCalculator is a free online chemistry calculator library for students, teachers, laboratory professionals, and scientists. Use our molar mass calculator, chemical equation balancer, and tools for stoichiometry, solution concentration, acids and bases, gas laws, and analytical chemistry. Each calculator shows the formula and method behind the answer and uses reviewed scientific data, so every result is reproducible and easy to verify.
Formula & Molecular Mass
Move between molecular formulas, composition, mass, amount, and particles.
- Molecular Weight CalculatorEnter a chemical formula. The calculator gives its molar mass, molecular weight, atom count, and element composition.
- Molar Mass CalculatorCalculate molar mass from an explicit chemical formula using versioned atomic-weight data.
- Grams to Moles CalculatorConvert a sample mass to moles from its chemical formula or molar mass.
- Moles to Grams CalculatorConvert moles to a selected mass unit from a chemical formula or molar mass.
- Moles CalculatorCalculate moles from an amount, sample mass, or particle count.
- Empirical Formula CalculatorFind the smallest whole-number formula from element masses or percentages.
- Molecular Formula CalculatorFind a molecular formula from an empirical formula and measured molar mass.
Reactions & Stoichiometry
Balance reactions and follow conserved amounts through stoichiometric ratios and yield.
- Chemical Equation BalancerBalance molecular or ionic equations with verified whole-number coefficients.
- Stoichiometry CalculatorBalance a reaction and calculate limiting reactants, excess amounts, and maximum product.
- Chemical Reaction CalculatorBalance a reaction and calculate the material result from the available reactants.
- Limiting Reagent CalculatorFind the limiting reactant, excess material, and maximum product for a reaction.
- Theoretical Yield CalculatorCalculate theoretical product mass from a balanced reaction and one reactant quantity.
- Percent Yield CalculatorCalculate percent yield, actual yield, or theoretical yield from the other two values.
Solutions & Concentration
Prepare and characterize solutions using concentration and dilution relationships.
- Molarity CalculatorCalculate molarity, solute amount, or solution volume from the known values.
- Dilution CalculatorCalculate any value in C1V1 = C2V2 and find the diluent volume to add.
- Concentration CalculatorCalculate molarity, mass concentration, percent concentration, ppm, or ppb.
- Serial Dilution CalculatorCreate a stage-by-stage serial dilution plan with transfer and diluent volumes.
- Molality CalculatorCalculate molality from solute moles or mass and the solvent mass.
- Normality CalculatorCalculate reaction-specific normality from molarity, equivalents, or equivalent weight.
- PPM CalculatorCalculate ppm by mass, volume, moles, density, percent, or ppb.
Acids, Bases & Equilibrium
Calculate ion concentrations, pH, buffers, and chemical equilibria.
- pH CalculatorCalculate pH, pOH, and ion concentrations for strong or weak acids and bases.
- pOH CalculatorCalculate pOH, pH, and ion concentrations for strong or weak acids and bases.
- Henderson-Hasselbalch CalculatorCalculate pH, pKa, acid amount, or conjugate-base amount for a buffer.
- Buffer pH CalculatorCalculate buffer pH after a strong acid or strong base addition.
- Equilibrium Constant CalculatorBuild the equilibrium expression and calculate K from species activities.
- Reaction Quotient CalculatorCalculate Q, compare it with K, and predict the reaction direction.
Gas Laws & Physical Chemistry
Relate pressure, volume, amount, temperature, density, and time-dependent change.
- Ideal Gas Law CalculatorCalculate pressure, volume, amount, or temperature with PV = nRT.
- Gas Law CalculatorUse Boyle, Charles, Combined, Avogadro, or Gay-Lussac gas laws.
- Boyle's Law CalculatorCalculate any pressure or volume in P1V1 = P2V2.
- Charles's Law CalculatorCalculate any volume or temperature in V1/T1 = V2/T2.
- Density CalculatorCalculate density, mass, or volume with unit conversion.
- Half-Life CalculatorCalculate radioactive decay or zero-, first-, and second-order reaction half-life values.
- Significant Figures CalculatorCount, round, format, add, subtract, multiply, or divide significant figures.
Electrochemistry
Connect reaction quotients, electron transfer, and electrical potential.
Atomic Chemistry
Explore elements, electron configurations, and oxidation states.
Analytical Chemistry
Inspect isotope patterns, formula candidates, structures, and spectra.
Biochemistry
Calculate biomolecule precursors, fragments, modifications, and polymers.
- This topic's calculators are held behind their scientific-data or release gate.
Applied Chemistry & Education
Use chemistry in pool treatment and education workflows.
- This topic's calculators are held behind their scientific-data or release gate.