I am afraid you are going to have to put a little more effort into your withholding than just claiming married, 1. That may seem like a logical withholding to you but, do you think it can cover all the different situations out there? Married, but only one spouse working; married, both spouses work, but earn very unequal amounts; married, both work and earn equal amounts; and that doesn't even get into whether you itemize deductions, etc.The previous advice is good, but even using the W-4 worksheet, check it against what income tax you owe this year. If your situation doesn't change significantly between this year and next, your taxes shouldn't change significantly either. In other words, you should be withholding (between you and your spouse) $4000/12 = $333 more a month than you are now. If the W-4 worksheet doesn't give a similar amount, keep researching!