Self-Employment Tax Calculator
Calculate self-employment tax — the Social Security and Medicare contributions that self-employed people pay on net business earnings, equivalent to both the employee and employer share of FICA combined. Use it to estimate quarterly tax payments and plan for the SE tax liability that's often the biggest tax surprise for new freelancers and business owners.
Last updated: September 2026
Formula below · 3 sources (IRS, ssa.gov, Wikipedia) · Updated Sep 2026
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About this calculator
The calculator follows IRS Schedule SE for tax year 2026. Net self-employment earnings are first multiplied by 92.35% (0.9235), which removes the employer-equivalent half of the tax from the base. If that adjusted figure is under $400, no SE tax is owed. Otherwise SE tax = 12.4% Social Security on adjusted earnings up to the 2026 wage base of $184,500, plus 2.9% Medicare on all adjusted earnings. Below the wage base this works out to 14.13% of net earnings (0.9235 × 15.3%). The 12.4% portion stops once adjusted earnings pass $184,500 (about $199,783 of net earnings), so the effective rate falls for higher earners and only the 2.9% Medicare portion continues. The 15.3% combined rate is 12.4% Social Security (6.2% employee + 6.2% employer) plus 2.9% Medicare (1.45% + 1.45%). Assumptions: no W-2 wages. If you also earned wages subject to Social Security tax, they use up part of the $184,500 base first and your SE tax will be lower (Schedule SE handles this). The 0.9% Additional Medicare Tax on earnings above $200,000 single / $250,000 joint is a separate tax figured on Form 8959 and is not included. Half of the SE tax is deductible as an above-the-line adjustment on Form 1040 Schedule 1, which reduces income tax but not SE tax. SE tax is owed on top of regular income tax, and quarterly estimated payments are generally required if you expect to owe $1,000 or more for the year.
How to use
Example 1 — Mid-range freelancer. Net business earnings $65,000 for 2026 (revenue minus business expenses). Enter 65000 for Net Earnings. Result: $9,184.21. Verify: 65,000 × 0.9235 = $60,027.50, and $60,027.50 × 15.3% = $9,184.21. ✓ This is on top of regular federal income tax and any state income tax; half of it ($4,592.10) is deductible when you figure income tax. Example 2 — Higher earner above the wage base. Net business earnings $250,000. Enter 250000. Result: $29,573.38. Verify: 250,000 × 0.9235 = $230,875 of adjusted earnings. Social Security applies only up to the 2026 wage base: $184,500 × 12.4% = $22,878. Medicare applies to all of it: $230,875 × 2.9% = $6,695.38. Total = $29,573.38. ✓ A flat 14.13% would have overstated this at $35,325. The separate 0.9% Additional Medicare Tax on adjusted earnings above $200,000 (single) adds about $278 on Form 8959 and is not included.
Frequently asked questions
Why do self-employed people pay both halves of FICA?
For W-2 employees, FICA (Social Security 6.2% + Medicare 1.45% = 7.65%) is split between employee and employer — the employee sees 7.65% deducted from each paycheck and the employer sends another 7.65% directly to the government. For self-employed people, you ARE the employer, so you owe both halves: the full 15.3% combined rate. This is one reason self-employment income faces effectively higher tax rates than equivalent W-2 income — you're paying the employer share that would otherwise be invisible. The IRS recognizes this and allows self-employed people to deduct half of their SE tax from their taxable income for income-tax calculation purposes (it's an above-the-line deduction on Form 1040 Schedule 1) — restoring rough parity with W-2 employees who don't pay tax on the employer's portion of FICA either.
What is the 92.35% adjustment factor?
When calculating SE tax, you multiply net earnings by 0.9235 before applying the 15.3% combined rate. The 0.9235 factor exists because self-employed people deduct half of their SE tax for income-tax purposes — and the calculation has to be circular-consistent (you can't deduct the SE tax until you know the SE tax). The 92.35% factor approximates this: 1 − (half of 15.3%) ≈ 1 − 0.0765 = 0.9235. So if your net earnings are $50,000, you multiply by 0.9235 to get $46,175, then by 0.153 to get $7,065 of SE tax. Below the Social Security wage base that is the same as a flat 14.13% of net earnings: 50,000 × 0.1413 ≈ $7,065. The adjustment is automatic on Schedule SE and is one reason SE tax calculations look more complicated than the underlying logic actually is.
Do I owe SE tax on every dollar of self-employment income?
No, with two important exceptions. First, if your net earnings from self-employment are under $400 in a year, you owe no SE tax at all — the de minimis threshold. Second, the Social Security portion (12.4% of the 15.3% combined rate) only applies up to the SS wage base — $184,500 of adjusted earnings in 2026. Above the wage base, only the Medicare portion (2.9%) applies. So a self-employed person with $300,000 of net earnings pays 14.13% on roughly the first $199,783 of net earnings (which is $184,500 after the 92.35% adjustment) and 2.9% × 0.9235 ≈ 2.68% on the rest; this calculator applies that cap automatically. A separate 0.9% Additional Medicare Tax applies once adjusted earnings pass $200,000 single / $250,000 married filing jointly; it is figured on Form 8959 and is not included here.
What are the most common mistakes people make with SE tax?
The biggest is being surprised by it entirely — new freelancers focused on income tax often forget SE tax exists, then face a tax bill 15+ percentage points larger than expected at filing time. The second is not making quarterly estimated tax payments and getting hit with underpayment penalties; if you expect to owe more than $1,000 in total tax, quarterly payments are mandatory. The third is forgetting to deduct half of SE tax from taxable income for income-tax calculation (it's automatic if you use tax software, but manual filers miss it). The fourth is failing to track legitimate business expenses, which directly reduce net earnings and thus SE tax — home office, mileage, professional development, software, marketing, and many other costs reduce both income tax AND SE tax. The fifth is not setting up an S-corp election once net earnings reach $80,000+, which lets you pay yourself a "reasonable salary" subject to FICA and take additional profits as distributions not subject to SE tax — a strategy that can save thousands annually.
When should I not use this calculator?
Adjust for W-2 wages: if you also earned wages subject to Social Security tax, they use up part of the $184,500 (2026) wage base, and this calculator, which assumes no wages, will overstate the Social Security portion. It is the wrong tool for S-corp or C-corp owners — those receive W-2 wages from their own corporation and pay FICA on those wages, not SE tax. Do not use it for income from rental real estate (passive income, not subject to SE tax for most landlords), capital gains, dividends, or other investment income — those have different tax treatments. It also doesn't handle clergy income (special SS-exemption rules), farm income (Schedule F has its own SE calculations), or partnership income (different rules for general vs limited partners). For any actual self-employment tax planning involving real money, use full tax software (TurboTax Self-Employed, FreeTaxUSA, H&R Block Self-Employed) or consult a CPA — especially for the first year of self-employment when quarterly estimates need to be set up correctly.