How much federal income tax is due on 14,900 for a single person tax year 2020?

[DMarkM1]

That depends on whether the 14,900 is gross income or taxable income.  If the 14,900 is gross income then at a minimum 12,400 is deducted as the standard deduction leaving 2,500 taxable income.  The tax rate on that figure is 10% so according to the tax tables the tax would be $251.  

Your tax return could also include other credits or deductions that would make that tax even lower.

If the 14,900 is taxable income then the tax rate is 10% on the first $9875 and 12% on the rest.  So according to the tax tables the tax would be $1594.  Again there could be credits that might reduce that tax even more.

[SweetieJean]

It also depends upon whether any of that income is from self-employment.