There is no simple answer to your question. The amount of tax you will have to pay depends on many factors - the amount of 1099-MISC income, the types and amounts of any other income, your filing status, deductions or credits you might be eligible for, etc., etc. The only way to determine how much you will owe is to complete your tax return. You can use TaxCaster to get an estimate. (See the comment posted by DoninGA above.) But TaxCaster will not show you the state tax. Or just prepare a trial tax return. If you use TurboTax Online you might want to do that with a separate account, so that your real tax return doesn't get mixed up with the trial. But be careful to keep track of your different accounts. If you use your regular TurboTax Online account for the trial, you can clear the return and start over when you are ready to do your real return.
As others have mentioned, you cannot report self-employment income in Free Edition. If you use TurboTax Online you will have to upgrade to at least Deluxe. If you have expenses related to the self-employment income you will have to upgrade to Self-Employed. Or you can use any edition of the CD/Download TurboTax software. The CD/Download software also lets you save multiple tax returns with different names, so you can do a trial return without interfering with your real return.
