Formal Charge Calculator
Calculate formal charges on atoms in molecules using valence electrons, lone pairs, and bonding electrons.
Formal Charge Calculation
2 lone pair(s)
2 bond(s)
Formula:
FC = V - L - B/2
V = valence electrons, L = lone pair electrons, B = bonding electrons
Quick Examples:
Formal Charge
0
O (neutral)
Calculation:
FC = 6 - 4 - 4/2 = 0
Common Example:
Water, alcohols, ethers
Octet Rule:
Satisfied (8 electrons)
Understanding Formal Charge
Formal charge is an accounting tool to track electron ownership in molecules. It helps determine the best Lewis structure (lowest formal charges, negative on more electronegative atoms). Unlike oxidation state, formal charge assumes equal sharing of bonding electrons.
Best Lewis Structure
Minimize formal charges and place negative FC on more electronegative atoms.
Sum of FC
Sum of all formal charges equals the overall molecular charge.