If you make ₦21,600,000 a year living in Nigeria, you will be taxed ₦6,699,680. That means that your net pay will be ₦14,900,320 per year, or ₦1,241,693 per month. Your average tax rate is 31.0% and your marginal tax rate is 32.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of ₦100 in your salary will be taxed ₦31.98, hence, your net pay will only increase by ₦68.02.
A ₦1,000 bonus will generate an extra ₦680 of net incomes. A ₦5,000 bonus will generate an extra ₦3,401 of net incomes.