Safety Checklist Program for Schools

X ppm = (Y mg/m³)(24.45)/(molecular weight)

or

Y mg/m³ = (X ppm)(molecular weight)/24.45

Fill in either the “ppm” value (X) or the “mg/m³” value (Y) AND the molecular weight of the compound. Then press the “Calculate” button.

ppm: mg/m³: molecular weight:

ppm value:
mg/m³ value:
Based on the Molecular Weight of:

Remember to consider significant digits in your use of the answer.

To determine molecular weight, add the atomic weights of all atoms present in the chemical formula for a particular substance. Periodic Table (courtesy of Los Alamos National Laboratory).