Federal Tax Withholding Estimator
The calculator allows you to estimate how much of your income should be withheld by your company. It will also allow you to figure out how much of your pretax contributions to retirement or medical insurance plans will be subsidized by the United States Government. These are the inputs to the calculator:

Your Gross Wages  You may enter your gross wages per period quickly and easily using the diamond on the slider marked 'Your Gross Wages'. If you would like to enter your wages with more precision, you may use the edit box to the right of the slider.
Retirement Contributions  Please enter the amount you contribute towards retirement and other activities with your pretax dollars. This will be counted as nontaxable thereby providing you with the tax savings that will effectively reduce this contribution. Again, you may use the slider to enter ballpark figures quickly or use the edit box to enter a more precise number.
Number of Allowances  Enter the number of exemptions you are claiming on your Form W-4. This will help determine how much or how little to withhold from your paycheck. The more exemptions you claim, the less federal taxes will be withheld.
Pay Frequency  The frequency of your paycheck can be entered by clicking in the edit box and selecting your choice from the resulting list of choices that pop down. This will determine your gross wages for the year.
Marital Status  You may indicate your marital status for the purposes of filing taxes by selecting one of the choices.
 
As you enter values for the above items, you will notice that the pie graph will indicate the proportion of your wages assigned to the different items. In addition, the status area will indicate how much the U.S. Government is subsidizing your pretax contributing cause. You can quickly evaluate your situation and also answer other questions such as:

   'How much will my take home portion be affected if I increase my allowances?'
'What if I get married?',
'What if I want to pay for my medical insurance premiums using pretax dollars?',
and more...
 
As always, the answers are only as far as a mouse click or a mouse drag away. Your answers appear in the results window at the bottom. Have fun playing with the planner.