Bonus & paycheck
Bonus Withholding Calculator
Compare your bonus withholding rate against the IRS supplemental wage flat rate. This tool explains why the withholding looks high. It does not calculate your final tax bill.
Bonus amount (gross) Before any deductions
$
Federal income tax withheld from this bonus Bonus paystub only
$
Did your total supplemental wages from this employer exceed $1 million this year?
Your effective withholding rate
-
IRS flat reference rate
22%
Difference
-
Status
-
This tool uses the IRS flat supplemental wage rate as a reference. Some employers use the aggregate method instead, so your rate may not match even if payroll is correct.
Your rate differs significantly from the flat supplemental rate. This often means your employer used the aggregate method, or combined bonus and regular wages in one payment. Check your paystub before assuming payroll made an error.
Related guide: Why is my bonus withholding so high?
How to find the numbers
Use the tax withheld for the bonus payment itself if your payroll system separates bonus and regular pay. Do not mix year-to-date federal withholding with the bonus-only withholding field.
Formula
actual rate = federal tax withheld from bonus / bonus amount.