If you make CHF 18'000 a year living in the region of Zurich, Switzerland, you will be taxed CHF 1'382. That means that your net pay will be CHF 16'618 per year, or CHF 1'385 per month. Your average tax rate is 7.7% and your marginal tax rate is 12.4%. 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 12.40, hence, your net pay will only increase by CHF 87.60.
A CHF 1'000 bonus will generate an extra CHF 876 of net incomes. A CHF 5'000 bonus will generate an extra CHF 4'380 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.