One way to help get an idea of what you can expect is with the tax refund calculator by H & R Block. While this is not a precise measurement of what you can expect, it will help relieve a little of the pressure by giving you an estimate.
This is perfect for those like me who like to know everything in advance or like to plan ahead. It also allows those who want to budget, the power to do so with a more accurate idea of what they are doing. Oh and the best thing about it - it's free. You can use the calculator at no charge and get the help you need. It may not relieve all of your stress but if it takes some of it away then that's always a good thing.