Self-Employment Tax Calculator | 1099 & Freelancer Tax Estimator

Freelance money looks bigger than it is. About 15.3% bigger.

Every new freelancer learns this the same way: the first year of 1099 income ends, the tax return gets done, and the number at the bottom is thousands higher than expected. Not because of income tax. Because of the tax nobody withholds, nobody mentions in the job posting, and nobody warns you about until April.

Self-employment tax is the freelancer’s version of FICA, the Social Security and Medicare taxes that quietly came out of every W-2 paycheck you ever got. The difference is that now you pay both halves: yours and the employer’s. Enter your profit in the calculator above and it breaks the whole bill apart so you can see exactly where the money goes.

How is self-employment tax calculated?

The formula the IRS uses on Schedule SE has three steps, and the middle one confuses everyone:

Step 1: Start with net earnings. That’s your freelance revenue minus deductible business expenses (your Schedule C profit).

Step 2: Multiply by 92.35%. This is the part people trip over. Here’s why it exists: an employee never pays FICA on the employer’s half of the contribution, so the IRS lets self-employed people shave 7.65% off the base before applying the rate. 100% minus 7.65% is 92.35%. It’s the tax code’s way of keeping things fair.

Step 3: Apply 15.3% to that reduced base. The 15.3% is really two taxes stacked: 12.4% for Social Security and 2.9% for Medicare.

Two wrinkles. The 12.4% Social Security portion stops at the annual wage base ($184,500 for 2026, $176,100 for 2025). Earn more than that and the Social Security part is done for the year; the 2.9% Medicare part has no cap and keeps going. And above $200,000 of earnings ($250,000 married filing jointly), an extra 0.9% Medicare tax joins in.

A worked example: $80,000 of freelance profit

Say your Schedule C shows $80,000 in net profit for the year. Here’s the Schedule SE math:

• SE taxable earnings: $80,000 x 92.35% = $73,880.00
• Social Security (12.4%): $73,880 x 12.4% = $9,161.12
• Medicare (2.9%): $73,880 x 2.9% = $2,142.52
• Total SE tax: $11,303.64

That’s the headline number: about $11,304 on $80,000 of profit, an effective SE tax rate of roughly 14.1%. And here’s the consolation prize the tax code offers: you get to deduct half of it ($5,651.82) from your income when calculating federal income tax. Note what that means carefully. The deduction lowers your income tax. You still owe the full $11,304 of SE tax itself.

Also note what this example doesn’t include: federal income tax, which you owe on top of SE tax, plus state income tax in most states. If you also sold investments during the year, that profit is taxed under yet another set of rules, and the capital gains tax calculator estimates what the sale adds to the pile. That’s why the standard advice for freelancers is to set aside 25-30% of every payment, not just the 15.3%.

Self-employment tax vs income tax (they’re separate bills)

This is the misunderstanding behind most freelancer tax shock. You don’t pay one tax. You pay two, calculated separately, on the same profit:

Self-employment tax is flat-ish: 15.3% on 92.35% of net earnings (with the Social Security cap). It funds Social Security and Medicare. Everyone with $400 or more of net self-employment earnings owes it.

Income tax is progressive: 10% to 37% on your taxable income after the SE tax deduction, the standard deduction, and everything else on your return.

On that $80,000 of profit, you’d owe the $11,304 of SE tax plus several thousand of income tax. Anyone who tells you freelancing “only” costs 15.3% is forgetting the second bill.

Quarterly taxes: the calendar that actually matters

Employees pay as they go through withholding. You have to do it yourself, four times a year, with Form 1040-ES. For the 2026 tax year the due dates are April 15, June 15, September 15, 2026, and January 15, 2027.

Miss them and the IRS can charge an underpayment penalty even if you pay everything in full when you file. The rule of thumb: if you’ll owe $1,000 or more after withholding and credits, make the quarterly payments.

Two practical ways to figure the amount. The simple way: estimate the year’s total tax and divide by four. The safe way: pay 100% of last year’s total tax in four installments (110% if your prior-year AGI topped $150,000). The second method is called the safe harbor, and it guarantees no underpayment penalty no matter what you actually earn this year. When income is unpredictable, safe harbor is your friend.

Who owes this, exactly?

Anyone with $400 or more of net self-employment earnings for the year. That covers freelancers, 1099 contractors, sole proprietors, gig workers, partners, and single-member LLC owners. You don’t need to form an LLC or register anything for the obligation to kick in. If the money arrives outside a W-2, the IRS generally treats it as self-employment income.

Side hustlers, take note: the $400 threshold applies to your freelance profit specifically, even if you also have a W-2 job. And if you have both, your W-2 wages use up the Social Security wage base first, which can reduce the SE tax on the freelance portion. Curious what the same income looks like as a regular paycheck, with withholding pulled out before you ever see it? The take-home pay calculator runs that version side by side in your head.

What the calculator assumes

• Net earnings = revenue minus business expenses (your Schedule C profit).
• SE tax = 15.3% on 92.35% of net earnings, with the Social Security portion capped at the wage base for the selected year.
• Half of the SE tax is deductible for income tax purposes (the calculator shows the deduction amount).
• Additional 0.9% Medicare tax above $200,000 single / $250,000 joint is included when applicable.
• Federal figures only. State taxes, the QBI deduction, and retirement contributions aren’t modeled.

This calculator gives an educational estimate, not tax advice. Self-employment tax interacts with your full return, so consult a qualified tax professional about your situation.