If you make 1,000,000 kr a year living in Norway, you will be taxed 328,123 kr. That means that your net pay will be 671,877 kr per year, or 55,990 kr per month. Your average tax rate is 32.8% and your marginal tax rate is 46.0%. 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 46 kr, hence, your net pay will only increase by 54 kr.
A 1,000 kr bonus will generate an extra 540 kr of net incomes. A 5,000 kr bonus will generate an extra 2,700 kr of net incomes.