Depending on your medical specialty, your areas of expertise, your experience and geographic region, your earning potential will vary widely. In general, the highest net salaries are to be earned in Saudi Arabia and the Emirates (no income tax), followed by Switzerland (low income tax, at least in some cantons). Germany is a high tax country as is France (where social contributions are not capped, so total deductions from your salary are high even if the income tax is low due to family circumstances), so in these countries net salaries tend to be lower. It should also be borne in mind that it is difficult for doctors aged 57 or over to be shortlisted by HR departments in Switzerland and in the Arab world.
For more information about salary ranges in your specialty, see the submenu of this page.