Assign oxidation number 0 to any free element
Assign oxidation number equal to the ion charge for a monoatomic ion
Use the sum of oxidation numbers in a neutral compound as 0
Use the sum of oxidation numbers in a polyatomic ion as the ion charge
Assign Group 1 metals oxidation number +1
Assign Group 2 metals oxidation number +2
Assign fluorine oxidation number -1 in all compounds
Assign oxygen oxidation number -2 in most compounds
Assign hydrogen oxidation number +1 with nonmetals
Assign hydrogen oxidation number -1 with metals
Assign halogens oxidation number -1 in most binary compounds
Adjust oxidation numbers to satisfy the total charge rule
Solve unknown oxidation numbers algebraically when needed