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Empirical Formula Calculator

Find the empirical (and molecular) formula from mass percentages or experimental masses.

Related tools

All Chemistry tools →
Chemical Equation BalancerBalance any chemical equation instantly by solving the element matrix exactly — even tricky redox reactions.Limiting Reactant CalculatorDetermine which reactant runs out first from the amounts you have and the balanced equation's mole ratios.Molar Mass CalculatorCompute the molar mass of any chemical formula, with per-element composition.Mole/Gram/Particle ConverterConvert between moles, grams and number of particles using molar mass and Avogadro's number.Interactive Periodic TableExplore the 118 elements — click any element for its atomic number, mass, category and properties.Stoichiometry CalculatorConvert between grams, moles and liters at STP across a balanced equation using mole ratios.Theoretical Yield CalculatorFind the theoretical yield of a product from reactant amounts, plus the limiting reactant and percent yield.Dilution calculator (C1V1 = C2V2)Find the final volume needed to dilute a solution to a target concentration.

Open Empirical Formula Calculator and you get an answer straight away, with no account to create. It sits under Chemistry in our catalogue, alongside Chemical Equation Balancer and Limiting Reactant Calculator.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is Empirical Formula Calculator?

Find the empirical (and molecular) formula from mass percentages or experimental masses.

When would I actually use this?

Preparing a solution at a stated concentration, working out how much of a reagent a reaction needs, and converting between mass, moles and volume.

What is the most common mistake?

Confusing molarity with molality. One is per litre of solution and the other per kilogram of solvent; they diverge as concentration rises, and only one of them is temperature-independent.

Is there a tool for the next step?

Limiting Reactant Calculator is the closest one after this: Determine which reactant runs out first from the amounts you have and the balanced equation's mole ratios.

What else is worth having open alongside it?

Molar Mass Calculator and Mole/Gram/Particle Converter — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Atomic masses are the IUPAC standard values. Results assume ideal behaviour and standard conditions unless the tool says otherwise — real solutions deviate, and lab work needs lab measurement.

Further reading

All guides →
How-toHow to Solve Stoichiometry Problems: Grams to Moles to Ratio to GramsEvery problem in the chapter is the same four moves. The mole ratio is the hinge, and it is the step students lose — worked here end to end, limiting reactant and percent yield included.How-toHow to Calculate Molar Mass, Including Parentheses and HydratesMultiply each atomic weight by its subscript and add. The only three places the arithmetic goes wrong are a subscript after a closing bracket, the hydrate dot, and a capital letter typed as a lowercase one.ExplainerThe Ideal Gas Law Explained: PV = nRT, R in Every Unit, and Where It BreaksPV = nRT holds when the gas is dilute and far from condensing. The value of R depends entirely on the units you feed it, and the temperature is never in degrees Celsius.How-toHow to Calculate a Dilution with C1V1 = C2V2Solve for the missing term, then convert the answer into a bench instruction. The step almost everyone skips is that the solvent you add is V2 minus V1, not V2.ExplainerHow Half-Life Works: What Is Left After 1, 3 and 10 Half-LivesOne half-life leaves 50%, three leave 12.5%, ten leave less than a tenth of a percent. The formula is a single line — the part worth understanding is why the answer never reaches zero.How-toHow to Calculate pH — And When the Weak-Acid Shortcut Stops WorkingFour routes for four kinds of solution, each worked with real numbers. Including the part most pages leave out: the square-root formula for a weak acid is an approximation with a validity limit, and it fails quietly.