Oxidation Number Calculator
Calculate the oxidation number (oxidation state) of an element in a chemical compound.
Compound Information
0 for neutral molecules, or charge for ions
Quick Examples
Oxidation Number of Mn
+7
in KMnO4
Redox State
Oxidized state (lost electrons)
Common Oxidation States of Mn
+2, +4, +7
Calculation
Total charge: 0
Sum of known oxidation numbers: 0 - (-7) = 7
Per Mn atom: (7) / 1 = 7
Rules Used
- • Oxygen: -2 (usually)
- • Hydrogen: +1 (with nonmetals)
- • Alkali metals: +1
- • Alkaline earth metals: +2
- • Sum of oxidation numbers = total charge
About Oxidation Numbers
The oxidation number (or oxidation state) represents the hypothetical charge an atom would have if all bonds were completely ionic. It is useful for tracking electron transfer in redox reactions, balancing redox equations, and naming compounds. The sum of oxidation numbers in a neutral compound is zero, while for ions it equals the total charge.