how do you calculate refund from federal tax?

Answer 1

You go to the post office and get a 1040A form or 1040EZ form and instruction booklet. All the instructions are in there, you can't figure it out without filling out the form, then looking up things. It's pretty easy, though.

Answer 2

You fill out a tax return to see how much your taxes for the year are. Then you compare that to what you paid in or had withheld. If you paid in more than your total taxes, you get the extra back as a refund. If your taxes are more than you paid in, then you owe.

Answer 3

You fill out a tax return!