Here I will show you how to calculate how much you have to pay Income Tax for a financial year if you have your Form 16 and if you know what is the Income Tax Rate. You need to know also what are the investment areas where you can save Income Tax. Of course there is a limit on investments. For example, the limit of investments is Rs. 1.5 lakh in 80C sections (it includes 80CCC and 80CCD sections).
Now when you get Form 16 from Organization, you see the Part A contains tax deductions on a quarterly and monthly basis and deposited to the Tax Department. So go to Part B where you see all your total gross salary, investment details and deductions.