<prompt> Human: Usually, my deductions from my gross for Federal, SS, Medicare, and Unemployment Insurance State of Alaska come out to about 21.3 of my gross, I take home about 78.7.This past pay period I had 8 days of approved PTO I took, but it was not figured in to my paycheck. After pointing it out and a weekend, I got a second check this morning for the missing 8 hours of PTO.The deductions on the new check seem to be almost exactly 40 of the check, not the usual 21.3. It isnt a gigantic chunk of money, but its my money that I earned, and itll eat at me if I dont investigate.Admittedly, I know just about squat about how deductions from paychecks work. Am I missing something that easily and obviously to the educated explains the difference? Is it deducted from differently because its PTO only? Is it because on my W4, Ive requested a flat additional amount be taken from each check, and that additional amount exceeds what would be deducted were no flat amount requested? The Federal Withholding seems to be about 15 of whats usually withheld from a paycheck that is normally 10 or 11 times the hours of this one, which would seem to be incorrect in terms of ratio, but may still be because my W4 says Take X from every check?.Edit: Much obliged ladies and gents. Appears to be correct, thanks for the advice.  <response>: The Social Security withholding should be 6.2 of your gross, and the Medicare 1.45 of your gross. If either of those is off, then there is definitely an error somewhere.For Federal Withholding, it comes down to how the payroll company runs their calculation. They have to estimate withholding, and most run the estimation by annualizing the gross amount of the check based on the standard pay period. So for instance, if you normally had a paycheck with gross 1000 and get paid weekly, they would estimate that youre going to make 52,000 for the whole year and withhold based on your actual tax due divided by the total number of pay periods for the year. For a 52,000 annual gross pay, with a single filer taking standard exemption and deduction, the total tax owed 2015 brackets would be 5156.25 52,000 - 4,000 - 6,300 - 37,450 25 6218.75. Divided up into 52 weekly pay periods, the Fed withholding would be 119.59 per check.The problem comes in one-off checks, where the gross is not based on any normal pay period, but still gets calculated as annualized for the same pay period. Like in my above example of a 1000week gross, if you got a 2000 bonus or PTO payout check it would be calculated estimating 104,000 a year gross instead of the 54,000 that is the real annual amount. Then the payroll company withholds for the higher tax bracket that a 104,000 salary would have. A true 104,000 annual pay would have total tax due of 21,431.25 divided into 52 pay periods for 412.14 withholding. 2015 numbers again: 18,481.25 104,000 - 4,000 - 6,300 - 90,750 28 The extra income is not taxed differently than any other earned income, but a bad estimate by the payroll company makes it look like it is getting taxed at a higher rate. When you file your taxes each year, the over-withholding of a bonus or other one-off check gets reconciled and youll get a refund. Im not sure if this is the case in your check, since the gross pay is actually smaller than you normally see, but if they used an odd pay period one week instead of two weeks it could explain the weirdness. Your take X from every check is also contributing because if you asked for 50 additional to be withheld from each check, it was probably withheld from this one-off check also. You could subtract the extra amount you asked to be withheld from the Fed withholding in this check and see if that makes your percentages closer to what youd normally see. 