Molar Mass Calculator
Parse a chemical formula, audit atom counts, sum atomic weights, and convert between formula mass, sample mass, and amount.
Introductory chemistryUse CalculatorCHEMISTRY · CALCULATE · UNDERSTAND
Free Chemistry Calculators
Free interactive chemistry calculators for students preparing for IGCSE, GCSE, A Level, AP Chemistry and university chemistry.
Mole Calculator
Find any one of mass, amount of substance, or molar mass from the other two.
Introductory chemistryUse CalculatorMolarity Calculator
Solve M = n/V for molarity, amount of solute, or final solution volume, with mol/mmol and L/mL conversions.
Introductory chemistryUse CalculatorDilution Calculator
Solve any one variable in M₁V₁ = M₂V₂ for a true solution dilution, with mol/L or mmol/L and L or mL.
General chemistryUse CalculatorStoichiometry Calculator
Balances a neutral molecular equation with exact integer arithmetic, then converts one known mass or amount into another species using coefficient ratios.
Introductory chemistryUse CalculatorIdeal Gas Law Calculator
Solve P, V, n, or T in PV = nRT with automatic SI-safe unit conversion.
Introductory chemistry and physicsUse CalculatorpH Calculator
Calculate pH, pOH, free hydronium, and free hydroxide concentrations in aqueous solutions. Default pKw = 14 is the common 25 °C value.
General chemistryUse CalculatorPercent Composition Calculator
Find each element's mass percentage from a chemical formula, or convert a known sample mass using that percentage.
High school to introductory general chemistryUse CalculatorBeer-Lambert Law Calculator
Solve A = εbc for absorbance, molar absorptivity, optical path length, or molar concentration, with cm/mm/m and mol/L/mmol/L/umol/L conversions.
Introductory analytical chemistryUse CalculatorOxidation Number Calculator
Find an element's oxidation number from a formula and explicit net charge, with selected introductory rules and exceptions.
General chemistry — rule-based, introductory scopeUse CalculatorAnswers are only the beginning.
Each chemistry calculator shows the formula, given values, substitution, calculation and final answer. Use the examples, check the units and learn from common mistakes. These tools are educational models, not a replacement for laboratory measurements or your course's assumptions.
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