If you make 300,000,- kr a year living in the region of Furesø, Denmark, you will be taxed 101,522, kr. That means that your net pay will be 198,478,- kr per year, or 16,540,- kr per month. Your average tax rate is 33.8% and your marginal tax rate is 39.9%. 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 39.87,- kr, hence, your net pay will only increase by 60.13,- kr.
A 1,000,- kr bonus will generate an extra 601,- kr of net incomes. A 5,000,- kr bonus will generate an extra 3,007,- kr of net incomes.