Stoichiometry & Reaction Engineering Calculators

All stoichiometry & reaction engineering calculators in one place.

Chemical Equation Balancer

Balance any chemical equation instantly with the smallest whole-number coefficients, an element-by-element atom check, and step-by-step working.

Limiting Reactant Solver

Find the limiting reactant, the excess reactant left over, and the theoretical yield of every product, with the equation balanced automatically and full step-by-step working.

Theoretical Yield Calculator

Find the theoretical yield of any product from any set of reactant amounts, with the limiting reactant identified automatically, an optional percent yield check, and full step-by-step working.

Percent Yield Calculator

Calculate percent yield, actual yield, or theoretical yield instantly with unit conversion, a labeled efficiency gauge, and full step-by-step working.

Actual Yield & Excess Reactant Finder

Predict the actual yield of any product from a percent yield, and find exactly how much of every excess reactant is left over, with the limiting reactant identified automatically and full step-by-step working.

Empirical Formula Calculator

Find the empirical formula from percent composition or lab masses, with mole ratios, whole-number subscripts, empirical formula mass, and an optional molecular formula — all with full step-by-step working.

Molecular Formula Calculator

Find the true molecular formula from an empirical formula and molar mass, or straight from percent composition and molar mass, with an atom-by-atom breakdown and full step-by-step working.

Oxidation State / Number Calculator

Find the oxidation number of every element in a compound or ion — type a formula like KMnO4 or Cr2O7^2- and get an instant, rule-by-rule breakdown with a chart, a balance check, and full step-by-step working.

Redox Half-Reaction Balancer

Balance any oxidation or reduction half-reaction in acidic or basic solution, with electrons, water, and H+/OH- added automatically, a full atom-and-charge check, and an advanced combiner that builds the overall balanced redox equation from two half-reactions.

Combustion Analysis (CHNS) Calculator

Turn CO2 and H2O combustion masses, or a CHNS elemental analyzer printout, into %C, %H, %N, %S and %O by difference, then build the empirical and molecular formula automatically — with a degree-of-unsaturation check and full step-by-step working.

Multi-Step Synthesis Overall Yield

Calculate the overall cumulative percent yield of a multi-step reaction sequence by multiplying every step's yield together, with final product mass, required starting material, and a full step-by-step cascade breakdown.

Atom Economy Calculator (Green Chemistry)

Find the percent atom economy of any balanced reaction from reactant and product formulas, with by-product waste mass, a mass-flow chart, reaction mass efficiency, E-factor, and a full step-by-step green chemistry breakdown.

Environmental E-Factor Calculator

Find the Sheldon E-factor of any chemical process from your raw material and product masses, with waste breakdown by category, mass intensity, mass productivity, an industry benchmark chart, and full step-by-step working.

Reaction Stoichiometry Mass-to-Volume

Convert the mass of any reactant or product into the volume of a gas it forms (or the reverse) using a balanced equation and the real ideal gas law, with STP, IUPAC STP, NTP, room temperature, and custom condition presets, a species-by-species comparison, and full step-by-step working.

Gas Stoichiometry at STP/NTP

Solve any gas stoichiometry problem at STP, NTP, SATP, or custom conditions — convert freely between mass, moles, and gas volume for every species in a balanced equation, with a live molar volume readout, an Avogadro's Law volume-to-volume shortcut, and full step-by-step working.

Hydrate Water Content / Water of Crystallization

Find the percent water of crystallization in any hydrate formula like CuSO4·5H2O, or work out the water content and hydrate formula from before-and-after heating lab data, with a donut chart, common-hydrate comparisons, and full step-by-step working.

Gravimetric Analysis Factor Calculator

Find the gravimetric factor between any analyte and its weighed precipitate form (like Fe from Fe2O3, or Cl from AgCl), then convert a precipitate mass into the mass and percent of analyte in your sample, with a common-pair comparison chart and full step-by-step working.

Percent Purity & Sample Assay Calculator

Find percent purity from a pure substance mass and sample mass, size the impure sample needed for a target pure mass, or run a full analytical sample assay against a reference standard, with a purity benchmark chart and full step-by-step working.