How many percent of taxes on 401K defaulted loan do I have to pay form 1099R?

[kakakusa-1]

I really like to know how much do I have pay in taxes on defaulted 401K loan for next year form1099R ? How many percent ?

[DoninGA]

Use the TurboTax calculator to estimate a tax refund or taxes owed - https://turbotax.intuit.com/tax-tools/calculators/taxcaster/

[Hal_Al]

There will be a 10% early withdrawal penalty, in addition to the income tax, if you are under age 59-1/2 (age 55 if left the service of that employer).
I believe the taxcaster tool does not  include the penalty, but you should verify that.
You will be taxed at you marginal income tax rate. But, the the 1099-R amount may push you into a higher tax bracket. If you are normally in the 15% tax bracket, most of it will be taxed at 15% (plus the 10% penalty) but some may may be taxed at 25% (35% with penalty)

[Hal_Al]

I'm told that the  taxcaster result does not include the 10% early withdrawal penalty.