The federal tax rate on your IRA withdrawal depends on your other income, among other factors. You can get a rough idea based on your 2020 tax return. On your 2020 Form 1040, what is your filing status and what is the amount of taxable income on line 15?
If it's an early withdrawal, the 10% penalty that Bsch4477 mentioned is in addition to the regular tax.
In most cases you will also have to pay state income tax on the IRA withdrawal. Every state has different tax rates and rules.