Write down the mass or percentage of each element
If given percentages, assume a 100 g sample
Convert each element’s mass to moles using atomic mass
Divide all mole values by the smallest mole value
Simplify the ratios to whole numbers if needed
If a ratio is close to a fraction, multiply all ratios by the same number to get whole numbers
Use the whole-number ratio as the subscripts in the empirical formula
Check that the final formula matches the simplest whole-number ratio of atoms