They will tell you how much you owe, but only if you file incorrectly :P
For Americans, if you didn't know, you can check your IRS transcripts at https://www.irs.gov/ to see exactly how much the IRS thinks you've earned.
For Americans, if you didn't know, you can check your IRS transcripts at https://www.irs.gov/ to see exactly how much the IRS thinks you've earned.