Chemical Formula Calculator

Chemical Formula Calculator. The Chemical Formula Calculator converts between chemical names and formulas — type "Water" to get H₂O, or type "H₂SO₄" to get sulfuric acid. Enter a chemical name or formula and optionally select a compound type to get the converted result, molecular weight (g/mol), number of elements, and compound classification. Toggle on step-by-step reasoning and an element composition chart for a full breakdown. Also try the Radioactive Decay Calculator (Nuclear).

Chemical Formula Calculator inputs

Enter either a chemical name or chemical formula

Results

Converted Result

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Compound Type

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Molecular Weight

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Number of Elements

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Results Table

How do I convert between chemical names and formulas?

Simply enter either a chemical name (like 'sodium chloride') or a chemical formula (like 'NaCl') in the input field. The calculator will automatically detect what you've entered and convert it to the other format. See also our use the Nuclear Decay Chain Calculator.

What types of chemical compounds are supported?

The calculator supports ionic compounds, covalent compounds with prefixes, binary acids (hydro-...-ic), oxoacids (...ate→...ic / ...ite→...ous), and hydrates with water molecules.

How are ionic compounds with transition metals handled?

For transition metals with variable charges, Roman numerals are automatically added when the charge can be determined from charge balance. For example, FeCl₃ becomes iron(III) chloride.

What is the step-by-step reasoning feature?

When enabled, this feature shows the logical steps used to convert between name and formula, including identification of compound type, ion charges, and naming rules applied.

How accurate is the molecular weight calculation?

Molecular weights are calculated using standard atomic masses from the periodic table and are accurate to 2 decimal places for most common compounds and elements.

Can the calculator handle polyatomic ions?

Yes, the calculator recognizes a comprehensive set of common polyatomic ions like sulfate (SO₄²⁻), nitrate (NO₃⁻), and phosphate (PO₄³⁻) in both directions.

What should I do if my compound isn't recognized?

Make sure to use proper chemical notation with correct capitalization (first letter uppercase, second lowercase). For complex compounds, try breaking them down into simpler components. You might also find our Neutron Count (N) — Isotope useful.