Convert moles into atoms or formula units
The moles to atoms converter starts with an amount of substance and the exact Avogadro constant. Choose moles of atoms for an elemental atom count, or choose molecules or formula units and enter a chemical formula. In formula mode, the first multiplication finds the number of formula units; a second multiplication uses each element subscript to find element-specific atoms. This two-stage display prevents a molecule count from being mislabeled as a total atom count.
Multiply moles by the Avogadro constant
The entity count is N = nNA, where NA is exactly 6.02214076 × 10²³ mol−1. Half a mole of atoms contains 3.01107038 × 10²³ atoms. The conversion is proportional, so doubling the mole amount doubles every reported count. Zero moles correctly gives zero entities. Scientific notation is preserved because expanding an entity count into ordinary digits makes exponents harder to audit and does not improve the precision of the original mole measurement.
Expand formula subscripts for element atoms
One mole of H2O contains one mole of water molecules, two moles of hydrogen atoms, and one mole of oxygen atoms. The total atom count is therefore three times the molecule count. Parentheses, brackets, and hydrate dots are expanded before element multipliers are applied. Enter the formula of one molecule or formula unit without a reaction coefficient; the mole field already states how many formula units are being counted.
Check entity labels and atom totals
First verify that the formula-unit count equals moles multiplied by the Avogadro constant. Then multiply that count by each displayed element subscript. Adding the element-specific counts should reproduce the total atom count. For ionic solids, “formula units” is generally more accurate than “molecules.” For a molecular substance, molecule count is appropriate. A mole of O2 molecules contains twice as many oxygen atoms, while a mole of oxygen atoms does not require that extra factor.
Counting limits and private use
The converter does not calculate sample mass, concentration, reaction coefficients, isotope abundance, ions formed in solution, or particles produced by dissociation. It counts the formula exactly as entered and cannot decide whether that formula describes the real sample. Significant figures come from the mole amount even though the Avogadro constant is exact. Keep the formula and entity label with any copied result so the large number retains its meaning.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.