Is there a quick way to get a ballpark figure as to how much you'll have to pay by looking at your W-2?

Answer 1

Not really. You need to prepare your tax return to see where you sit. There are way too many complexities to the calculations even in a simple tax return to make any kind of meaningful estimate from looking at a single W-2.

Answer 2

Yes, if you go to the Library or Post Office and get a book corresponding with the form you intend to file, it will give you a ballpark figure of what you owe, vs what you'll get back.

Answer 3

If you are single with no dependents, look at Box 1, subtract about $8,000. Then take 10% of that. You will owe at least that much. Compare that number with Box 2. If Box 2 is less, you are going to owe at least the difference (and you could or more if your income is in a higher tax bracket).

If you have other filing status or dependents you can do a similar calculation using the standard deduction and exemptions...not going to do that here, but you get the idea.