How to Use the W-2 + 1099 Combined Tax Calculator
If you have a regular job plus a side gig, your W-2 wages already have payroll and income tax withheld, but your 1099 self-employment income does not. At tax time, that self-employment income is combined with your wages for federal income tax, and it also triggers self-employment (SE) tax to cover Social Security and Medicare.
This calculator combines your W-2 wages and net 1099 income, applies the SE tax to your self-employment income (accounting for the Social Security wage base), deducts half of the SE tax, then applies federal income tax brackets to your combined taxable income.
Because both income tax brackets and the extra SE tax apply, side income is often taxed at a noticeably higher effective rate than an equivalent raise at your W-2 job — planning for quarterly estimated payments can help avoid a surprise bill.
Frequently Asked Questions
Self-employment (SE) tax covers Social Security and Medicare for income not already taxed through W-2 payroll withholding. It's 15.3% of 92.35% of your net 1099 income (12.4% Social Security up to the annual wage base, plus 2.9% Medicare with no cap).
Yes, half of your self-employment tax is deductible from your taxable income, which slightly lowers your federal income tax. This calculator applies that deduction automatically before calculating income tax.