# How does one calculate oxidation states? [duplicate]

For example, how could I calculate the oxidation state of lead in $$\ce{PbS}$$? Or for that matter how would I calculate it for sulfur? Or I have two unknowns, for example sulfur in $$\ce{PbSO4}$$? Do I assume that lead has a 2+ charge and therefore a +2 oxidation state and since it has ? Or is there something that I am missing? Additionally, from all the reading that I've done I've only found a rule for bromine, chlorine, and iodine in binary compounds, what happens if they are in a compound with more than two elements? For example $$\ce{COCl2}$$. How would someone calculate the oxidation state of carbon? This stuff is really confusing for me and I apologize if this seems really basic or I have missed something.

I have read the introduction to oxidation states post, and it was a very well written answer, however it still did not help things click. I still feel like I am missing something