Self-Employment Tax Calculator

Self-employment tax is the freelancer/contractor equivalent of the Social Security and Medicare taxes a W-2 employer would normally withhold and match. It's 15.3% of your net profit — 12.4% for Social Security (up to the annual wage base) and 2.9% for Medicare (uncapped) — and it's separate from ordinary income tax.

Only 92.35% of your net profit is subject to SE tax (an IRS adjustment that roughly mirrors how a W-2 employer's share of FICA isn't taxed as your income). That amount is taxed at 12.4% for Social Security up to the year's wage base, plus 2.9% for Medicare with no cap, plus an extra 0.9% Medicare surtax on earnings above $200,000 (single) or $250,000 (married filing jointly).

Yes, on your self-employment profit — but the Social Security portion only applies up to the annual wage base across all your earnings combined. If your W-2 wages already used up most of that base, less (or none) of your self-employment income will owe the 12.4% Social Security piece, though the 2.9% Medicare piece still applies to all of it.

You can deduct half of what you pay in self-employment tax as an above-the-line adjustment to income on your federal return. It doesn't reduce your SE tax itself, but it does lower the income tax you owe on top of it — this calculator already includes that deduction in the breakdown.

Self-employment tax funds Social Security and Medicare and is a flat 15.3% (with the wage base cap noted above). Federal and state income tax are separate, calculated on your taxable income using progressive brackets. You owe both — SE tax doesn't replace income tax, it's in addition to it.

Since no employer withholds tax on your behalf, the IRS expects quarterly estimated payments. Underpaying can trigger a penalty even if you pay the full balance by the April filing deadline. Our quarterly estimated tax calculator turns this same profit estimate into four due-date payments.