The percentage of wages withheld for taxes by the federal government varies depending on marital status, annual income, deductions, and exemptions. The amount withheld per pay period is at your disposal, you can choose to claim yourself as a dependent, and have a lower percentage withheld, or claim zero and have the income tax withheld at a higher percentage. A benefit of claiming zero is you most likely will not end up owing at the end of the year, and many end up with a sizable refund.
The best way to figure out what to claim is to figure out using an annual chart released by the IRS what your federal tax for the year will be, and divide it among pay periods.
The Federal Tax Rate schedule can be found on IRS.gov, and will outline the minimum tax for that bracket, as well as the percent at which the remaining income is taxed. For example, if you are married with no children, and you and your spouse file jointly, earning between $15,100 and $61,300, you will automatically be taxed $1,510 plus 15% of the amount over $15,100. The higher the income, the higher both the standard tax for that bracket, and the percentage for earned income over that
amount, will be.
It depends on many, many things. not the least of which is what you consider tax. Many people group all their withholdings as a type of tax, but many may not be. Workers Comp, Unemployment, even FICA are all really more an insurance payment than a withholding against an income tax.
The amount of tax withheld also depends on may things. obviously which state (or even city) your in, the amount of income your projected on earning over the year, (which helps determine your tax bracket and the percent that may be needed), as well as your filing status, number of dependents and other deductions. All these things can be adjusted for your circumstances by properly and completely filling out (or changing) the Form W-4 all employers ask you to.
Finally, there are a number of different legal ways for the payroll provider to calculate certain aspects of the amount to withhold. but overall they make only a small difference.
Remember, anything withheld is just being done as an estimated installment payment toward whatever tax, if any, you do ultimately owe. If too much is withheld, it is refunded. (Too little, and you could pay a penalty). Again, adjusting your W-4 is the way to correct for any of these circumstances.