If you make CHF 20'000 a year living in the region of Zurich, Switzerland, you will be taxed CHF 1'633. That means that your net pay will be CHF 18'367 per year, or CHF 1'531 per month. Your average tax rate is 8.2% and your marginal tax rate is 14.5%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of CHF 100 in your salary will be taxed CHF 14.54, hence, your net pay will only increase by CHF 85.46.
A CHF 1'000 bonus will generate an extra CHF 855 of net incomes. A CHF 5'000 bonus will generate an extra CHF 4'273 of net incomes.
NOTE* Withholding is calculated based on the Zurich tables of Switzerland, income tax. For simplification purposes some variables (such as marital status and others) have been assumed. This document does not represent legal authority and shall be used for approximation purposes only.