# How can I calculate formal charge?

##### 1 Answer

The formula for calculating the formal charge on an atom is simple.

Formal charge = [# of valence electrons] – [electrons in lone pairs + 1/2 the number of bonding electrons]

Since the number of bonding electrons divided by 2 is equal to the number of bonds surrounding the atom, this formula can be shortened to:

Formal Charge = [# of valence electrons on atom] – [non-bonded electrons + number of bonds].

Let's look at an example. Take the compound

Next, let's look at the hydrogen atoms in

Sources: http://www.masterorganicchemistry.com/2010/09/24/how-to-calculate-formal-charge/