Your nation's tax rate is the percentage of your citizen's individual income that you take each day as taxes. For example, a tax rate of 25% when your citizens earn $100 would give you $25 a day per citizen. This number is multiplied by your total number of citizens (not including soldiers) to give the amount you earn daily in taxes. It is almost always best to set your tax rate to 28%. The tax rate may be changed in the "Edit my Nation" page.