Taxes are roughly 50% for someone making 120k. Maybe closer to 45% when its all said and done. There's state income taxes, federal income, Medicare and social security, sales tax, property tax, real estate taxes, and then special taxes on stuff like gas, guns, phone bills, hotels and car rentals, airplane tickets, etc.
For all our complaints about how evil taxes are we sure have a whole lot of them!
If you are normal. If you're particularly rich then it'll be different because the majority of your assets aren't from income and there's all kinds of loopholes. If you're particularly poor taxes will be significantly lower but the threshold is pretty low... The poverty line for a family of 4 is shockingly low.