The tax amount is all depending on your status, (single, married, head of household, dependants) and how much you make totally, weather you have a house you can deduct interest and other variables. To make a rough estimate, I would put away about 12-15 percent to be safe. I have been doing my taxes and my children's for years. I have never paid more that about 13 percent in federal taxes and that was when I only had my wife and myself as deductions and was making around 80k, now if you break other thresholds like 100k/150k/200k/250k the percent goes up.