Chemical Name Calculator
Choose a cation and an anion to generate a charge-balanced ionic formula and its systematic compound name.
Select the ions
Compound result
Charge-balance details
| Ion | Symbol | Charge | Subscript in formula | Charge contribution |
|---|---|---|---|---|
| Sodium | Na⁺ | +1 | 1 | +1 |
| Chloride | Cl⁻ | – 1 | 1 | – 1 |
How to use the chemical name calculator
What this calculator does
This calculator combines one listed cation with one listed anion, balances their electrical charges, writes the empirical formula, and applies standard introductory naming rules. It is useful for checking homework, preparing lab notes, building flash cards, and verifying the smallest whole-number ion ratio before writing a formula. It does not predict whether a compound is stable, soluble, safe to handle, or likely to form under real laboratory conditions.
When to use it
Use it when converting a familiar ion pair into a formula, checking a transition-metal Roman numeral, practicing polyatomic-ion parentheses, or confirming why a formula needs subscripts such as CaCl₂ or Al₂(SO₄)₃.
How to calculate
- The calculator opens with sodium and chloride as a complete demonstration, so the result and Excel workbook are immediately available.
- Choose a value in Cation symbol. The list shows the ion formula and charge; cations with more than one possible charge are separate choices.
- Choose a value in Anion symbol. The result updates immediately with the balanced formula, compound name, ion counts, and charge table.
- Read Compound result and Charge-balance details. The positive and negative totals must have equal magnitude.
- Select Download Excel to export the current ions, formula, name, counts, charges, and notes as a validated workbook.
- Select Reset to clear both ion choices and all calculated content. Export is then disabled until both required selections are complete again.
Input guide
Cation symbol is required and accepts one listed positive ion, for example Fe³⁺. A larger charge can reduce the number of cations required, depending on the anion. A common mistake is choosing Fe²⁺ when the intended name contains iron(III). Anion symbol is also required and accepts one listed negative ion, for example SO₄²⁻. Polyatomic ions keep their conventional names; monatomic anions normally change to an “-ide” ending. Do not infer a charge from an unlisted spelling – select the exact ion instead.
Output guide
Compound name gives the ionic name, including a Roman numeral for variable-charge cations. Formula gives the reduced empirical formula. Cation count and Anion count are the subscripts implied by charge balance; a displayed count of 1 is omitted from the formula. Total positive charge and Total negative charge show the contribution from each side, and their sum is exactly zero for every valid result. The table repeats each ion, charge, required subscript, and contribution so the balancing step is auditable.
Worked example
The opening example uses Na⁺ and Cl⁻. Their charge magnitudes are both 1, so the least common multiple is 1. One sodium ion contributes +1 and one chloride ion contributes – 1; the net charge is zero. The smallest ratio is therefore 1:1, the formula is NaCl, and the name is sodium chloride. For background on ion formation and ionic formulas, see the LibreTexts guide to names and formulas of ionic compounds.
How charge balancing and naming work
An ionic formula represents electrical neutrality. The calculator finds the least common multiple of the absolute cation and anion charges, then divides that value by each charge magnitude to obtain the smallest whole-number subscripts. For Al³⁺ and O²⁻, the least common multiple is 6, so two aluminum ions provide +6 and three oxide ions provide – 6, giving Al₂O₃.
Names place the cation first. Fixed-charge metal and polyatomic cation names remain unchanged. When a cation can have more than one listed charge, the charge is shown with a Roman numeral, such as copper(II). Monatomic anions generally use an “-ide” ending, while common polyatomic ions retain names such as nitrate, sulfate, hydroxide, and carbonate. The IUPAC Gold Book definition of an ion provides the formal terminology, and the OpenStax discussion of molecular and ionic compounds explains the underlying distinction.
Parentheses matter only when more than one copy of a polyatomic ion is required. Calcium hydroxide is Ca(OH)₂, not CaOH₂, because the subscript applies to the entire hydroxide group. Formulas are empirical ratios, not necessarily isolated molecules; an ionic solid is better understood as an extended lattice. For a broader nomenclature reference, consult the IUPAC nomenclature Color Books overview.