If you make 1,200,000 GH₵ a year living in Ghana, you will be taxed 409,887 GH₵. That means that your net pay will be 790,113 GH₵ per year, or 65,843 GH₵ per month. Your average tax rate is 34.2% and your marginal tax rate is 35.5%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 GH₵ in your salary will be taxed 35.50 GH₵, hence, your net pay will only increase by 64.50 GH₵.
A 1,000 GH₵ bonus will generate an extra 645 GH₵ of net incomes. A 5,000 GH₵ bonus will generate an extra 3,225 GH₵ of net incomes.