Formal Charge Calculator
Enter the Lewis-structure counts for one atom to apply FC = V − 2L − B.
A QUICK WALKTHROUGH
How to use this tool
- Enter the atom’s valence-electron count.
- Enter its lone-pair count and total bond-order count.
- Calculate the formal charge and review the substituted equation.
What the inputs mean
V is the neutral atom’s valence-electron count, L is the number of lone pairs on that atom, and B is the sum of bond orders attached to it. A single bond contributes 1, a double bond 2, and a triple bond 3.
Fixed calculation scope
This calculator evaluates the counts you enter for one atom. It does not draw, infer, validate, or rank Lewis structures and does not calculate oxidation state.
GOOD TO KNOW
Common questions
Is a double bond counted once or twice?
Enter 2 in the bond-order sum for a double bond.
Is formal charge the same as oxidation state?
No. Formal charge splits bonding electrons equally; oxidation-state rules assign them by electronegativity.