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: May 2026
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About this calculator
The formula is: SE tax = net earnings × 0.1413. The 14.13% rate is the effective SE tax rate after applying the standard 92.35% adjustment: SE tax = net earnings × 0.9235 × 0.153 ≈ 14.13%. The 15.3% combined rate consists of 12.4% for Social Security (matching the 6.2% employee + 6.2% employer rates) plus 2.9% for Medicare (matching the 1.45% + 1.45% employee + employer rates). The 92.35% adjustment exists because self-employed individuals are allowed to deduct half of their SE tax for income-tax purposes; the 92.35% factor (which equals 1 − 7.65%/2 ≈ 1 − 0.0765/2, simplified) approximates "net earnings minus the half-SE-tax deduction" without requiring iteration. Edge cases: net earnings under $400 are exempt from SE tax. Net earnings ABOVE the Social Security wage base ($168,600 in 2024) escape the 12.4% Social Security portion on the excess — only the 2.9% Medicare portion (plus 0.9% additional Medicare above $200K/$250K) applies above the wage base; the formula's flat 14.13% does NOT account for this and overstates SE tax for high earners. Self-employed individuals also pay half of the SE tax as an above-the-line deduction on Form 1040, reducing their income tax (separately from this calculator). SE tax is on top of regular income tax, which is why self-employment effectively faces marginal rates 15+ percentage points higher than W-2 employment at the same income level. Quarterly estimated payments are required if total tax owed will exceed $1,000.
How to use
Example 1 — Mid-range freelancer. Net business earnings $65,000 for the year (revenue minus business expenses). Enter 65000 for Net Earnings. Result: $9,184.50. Verify: 65000 × 0.1413 = $9,184.50. ✓ This is on top of regular federal income tax (roughly $7,500–$9,000 for a single filer at this income level after the standard deduction and half-SE-tax deduction) and any state income tax — total federal liability roughly $16,500–$18,000, plus state. Quarterly estimated payments would be ~$4,250 each. Example 2 — Higher earner partially above wage base. Net business earnings $200,000. Enter 200000. Result: $28,260. Verify: 200000 × 0.1413 = $28,260. ⚠ This OVERSTATES the actual SE tax because the Social Security portion (12.4%) only applies to the first $168,600 in 2024. The correct calculation: $168,600 × 0.9235 × 0.124 (SS portion) + $200,000 × 0.9235 × 0.029 (Medicare portion) ≈ $19,310 + $5,357 = $24,667, plus additional Medicare on the portion above $200K (which is just at the threshold). The calculator's flat 14.13% only works accurately for net earnings under the SS wage base.
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. The same result comes from the calculator's simplified flat 14.13% rate: 50,000 × 0.1413 ≈ $7,065 (matches within rounding). 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 — $168,600 in 2024. Above the wage base, only the Medicare portion (2.9%) applies, plus an additional 0.9% Medicare on net earnings above $200,000 single / $250,000 married. So a self-employed person with $300,000 of net earnings pays SE tax on the full amount, but at different effective rates: 14.13% (the flat rate this calculator uses) on the first $168,600, then a much lower 2.9% × 0.9235 ≈ 2.68% on income from $168,600 to $200,000, then 3.8% × 0.9235 ≈ 3.51% on income above $200,000 (the additional Medicare kicks in). This calculator's flat-rate math is accurate only below the SS wage base.
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?
Skip it if your net earnings exceed the Social Security wage base ($168,600 in 2024) — the flat 14.13% formula overstates SE tax above that threshold because the SS portion stops applying. Use a tiered calculator or tax software that applies the correct rates by income tier. 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.