Jim Wang at US News & World Report has an interesting breakdown of what the marriage penalty tax is costing you. For some people there is a “marriage bonus” where taxes are lower because of the different tax rates between single and married filers.

See: http://money.usnews.com/money/blogs/my-money/2014/03/11/how-much-the-marriage-tax-penalty-will-cost-you

See also: TurboTax – Top 10 Tax Deductions You’re Not Taking.