Moles to Particles Calculator

How it is calculated

The tool multiplies the amount of substance in moles by the Avogadro constant: N = n × 6.02214076×10²³, where n is moles and N is the number of elementary particles (atoms, molecules, ions or formula units, whichever you are counting). It uses the exact value fixed in the SI definition of the mole. The answer is printed in scientific notation with five significant figures, in the form 1.5055e+23, which means 1.5055 × 10²³. The amount must be greater than zero; zero or negative input shows no result. Amounts below 0.01 mol are echoed in scientific notation too (0.001 mol appears as 1.0000e-3 mol) so they never print as 0.0000. The result counts only the one kind of particle you specify; to count the atoms inside molecules, multiply again by the number of atoms per molecule.

Common mistakes

• Entering grams instead of moles. This tool starts from moles; to convert from mass first divide by the molar mass (g/mol), for example 18.015 g/mol for water.
• Confusing molecules with atoms. The result is the count of whatever particle you are counting, so for H₂O the atom count is three times the molecule count and for O₂ it is twice.
• Reading 1.5055e+23 as 1.5055 × 23 or as 1.5055 with 23 zeros. The e+23 means × 10²³, i.e. the decimal point moved 23 places.
• Rounding Avogadro's number to 6.02 early. Using 6.02×10²³ instead of the full constant changes the fourth significant figure and can shift a result you are comparing to a textbook answer.
• Typing a negative or zero amount of substance. Only positive values give a result.