If you make 300,000,- kr a year living in the region of Københavns, Denmark, you will be taxed 99,861, kr. That means that your net pay will be 200,139,- kr per year, or 16,678,- kr per month. Your average tax rate is 33.3% and your marginal tax rate is 39.2%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100,- kr in your salary will be taxed 39.19,- kr, hence, your net pay will only increase by 60.81,- kr.
A 1,000,- kr bonus will generate an extra 608,- kr of net incomes. A 5,000,- kr bonus will generate an extra 3,041,- kr of net incomes.