The current top federal tax rate is 39.5%. For $500k, that’s $183k. You net $317k. Extrapolate accordingly.
There are additionally, varying state, local and source-specific taxes, like capital gains taxes, for example.
As your income increases, you rise into higher percentage tax brackets (22%, 28%, 35%) as you reach certain income thresholds.
(I don’t have the specific increments at hand, I pay my accountant to handle such things)
All of these rates are about change under the new Tax Reform Act passed by Congress. As I understand it, lower (federal) tax rates await most brackets.