@Clbh4900
No one can really tell you that.
The 25,000 is added to all your other income for the entire year, so there is no way for any of us to tell what tax bracket you will be in, after whatever deductions you have. If your other income is fairly low, the standard 20% federal withholding should be enough...but if your other income is high, see if you can get them to withhold 25 or 30%. (Plus 5-10% for your state if it has an income tax).
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If you are using the 2018 desktop software, you could model it in a second test copy of your 2018 tax file (first bumping up your age a year), and adding in that extra 25,000. Tax rates are close enough to do that for a quick calc..probably can't get a closer estimate anyhow.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
