How can I know how much I owe back taxes on my last check stub from my employer?

[IsDatJacob]

Federal taxes wasn’t taken out of my check for 2 pay periods beginning of this year

[DoninGA]

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