what is the % of taxess withheld for federal taxes with 1 exmpt.?

Answer 1

That depends upon your gross pay. Could be anything from 0% to 35% for Federal income tax plus 7.65% for FICA.

Go here for some handy estimators: http://www.paycheckcity.com

Answer 2

IRS Circular E (Publication 15) details the federal taxes withheld based on the payroll period and the paid amount. One withholding exemption is $3400 per year...or $65.38 per weekly pay period, $130.77 per biweekly, $141.67 per semimonthly, or $283.33 monthly.
For a biweekly payroll period, your employer will compute the federal tax to withhold by subtracting one withholding allowance ($130.77) from your gross pay and then compute the tax on a sliding schedule. For a single person that scale is-
Over $102 but less than $389 ---> 10% of amount over $102
Over $389 but less than $289 ---> $28.70+15% of amount over $389
Over $1289 but less than $2964---> $163.70+25% of the amount over $1289

Go to the IRS web page and search for Publication 15. The withholding tables are on pages 37 and 38.

Answer 3

http://www.irs.gov

it isn't a flat percentage, it changes according to your income and your employer's pay schedule (monthly, weekly...)

your social security and medicare will total .0765%

plus you'll probably have state taxes, and possibly unemployment