Molecular Formula Calculator Formula
Understand the math behind the molecular formula calculator. Each variable explained with a worked example.
Formulas Used
Multiplier (n)
multiplier = actual_molar_mass / empirical_massVariables
| Variable | Description | Default |
|---|---|---|
empirical_mass | Empirical Formula Mass(g/mol) | 30.03 |
actual_molar_mass | Actual Molar Mass(g/mol) | 180.16 |
How It Works
How to Find the Molecular Formula
Formula
n = actual molar mass / empirical formula mass
Multiply all subscripts in the empirical formula by n to get the molecular formula.
Worked Example
Empirical formula CH2O (30.03 g/mol), actual molar mass 180.16 g/mol.
empirical_mass = 30.03actual_molar_mass = 180.16
- 01n = 180.16 / 30.03
- 02n = 6
- 03Molecular formula = C6H12O6 (glucose)
Frequently Asked Questions
What if n is not a whole number?
It should round to a whole number. If not, check your empirical formula mass and actual molar mass for accuracy.
Can the molecular formula equal the empirical formula?
Yes, when n = 1. For example, water has both empirical and molecular formula H2O.
How do I find the actual molar mass?
From mass spectrometry, freezing point depression, or other experimental methods.
Ready to run the numbers?
Open Molecular Formula Calculator