Help with “IF” spreadsheet formula

I am making a spreadsheet to help calculate commissions. The percentage I need depends on a certain amount of volume entered. So I want to be able to put in A1 the sales volume and then in A2 if the number in A1 is between 0 and 7500 it will equal 15% 7500 to 15000 it will equal 20% and 15000 to 50000 it will equal 25% how would I write that formula?

TIA

HeyRobi