Is there a way I can look up or calculate another person's net worth through math? Is a person who is making credit card, car, house, etc payments owe more that what they have equal they are worth less then nothing?
Yes, if they give you a list of assets and liabilities, you can calculate any person's net worth by adding up all the assets and subtracting all the liabilities from the total.
Unless they're on forbes' list, you probably won't be able to look up someone's net worth (it's also extremely private information). it's just value of assets - value of liabilities.... If you have those numbers it's fairly easy (mint used to actually display it).