Formulas and 2026 figures checked & updated: July 2026
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How to Use the Self-Employment Tax Calculator
- Enter Schedule C-style net profit after business expenses.
- Enter Social Security wages from other employment.
- Choose a rough federal marginal rate and the correct Additional Medicare threshold for your filing status.
- Use the quarterly reserve as a budgeting illustration, then calculate actual estimated payments with current IRS forms.
What This Calculator Does
Self-employment tax is the Social Security and Medicare tax generally borne by someone with net earnings from self-employment.
Income tax is separate, so the tool also shows a clearly labeled reserve illustration rather than presenting SE tax as the full tax bill.
Formula
Net earnings = Profit × 92.35%; SE tax = 12.4% Social Security (up to remaining 2026 wage base) + 2.9% Medicare + applicable 0.9% Additional Medicare TaxThe calculator applies the statutory 92.35% net-earnings factor, a 12.4% Social Security component limited by the 2026 $184,500 wage base after entered Social Security wages, and 2.9% Medicare. It illustrates the 0.9% Additional Medicare Tax above the entered filing-status threshold. The income-tax reserve applies an entered marginal rate after an estimated deduction for one-half of the regular SE tax. It does not calculate brackets, QBI, credits, state tax, safe-harbor payments, or every Schedule SE exception.
Examples
$100,000 net profit
No other Social Security wages and a 22% marginal-rate illustration.
The calculator applies 92.35% before computing the Social Security and Medicare components.
Related Calculators
Try another tool to complete the picture
Methodology
The calculator applies the statutory 92.35% net-earnings factor, a 12.4% Social Security component limited by the 2026 $184,500 wage base after entered Social Security wages, and 2.9% Medicare. It illustrates the 0.9% Additional Medicare Tax above the entered filing-status threshold. The income-tax reserve applies an entered marginal rate after an estimated deduction for one-half of the regular SE tax. It does not calculate brackets, QBI, credits, state tax, safe-harbor payments, or every Schedule SE exception.
Frequently Asked Questions
Why is profit multiplied by 92.35%?+
Schedule SE generally applies Social Security and Medicare rates to 92.35% of net self-employment earnings, reflecting the employer-equivalent adjustment.
Why enter W-2 Social Security wages?+
Employee wages and self-employment earnings share the annual Social Security wage base. Existing wages reduce the remaining self-employment earnings subject to the 12.4% component.
Is half of all SE tax deductible?+
The above-the-line deduction generally corresponds to the employer-equivalent portion of regular self-employment tax. The Additional Medicare Tax is not included in this calculator's deductible-half figure.
Is the Self-Employment Tax Calculator exact?+
The arithmetic follows the formula shown on this page, but the result is an estimate because real-world rates, fees, taxes, timing, and provider rules can differ. Use the actual figures from your lender, plan, or agency before making a decision.
Does this calculator store my financial information?+
No. The calculation runs in your browser. Saved results remain in local browser storage and are not submitted as an application or professional financial record.
Can I save my results?+
Yes. Use “Save results” to store a snapshot. Without an account it remains in this browser. If you log in, saved scenarios sync securely to your SmartRates account so they are available on your other devices.
How do I share my calculation?+
Click “Share” in the toolbar to copy a link (or open your device’s share sheet). The link encodes your exact inputs, so whoever opens it sees the calculator pre-filled with the same numbers and the same result.
Can I email my calculator results?+
Yes. Click “Email results” to open your default email application with the current inputs, results, and calculator link already included. Review the message and choose the recipient before sending.
Can I export or print my results as a PDF?+
Yes. Click “Export PDF” to open a clean, printable summary of your inputs and results that you can save as a PDF or print. It includes a timestamp and a link back to the calculator.
How accurate are the calculator results?+
The arithmetic follows the formula and assumptions documented on this page. The result is still an estimate because actual rates, fees, taxes, timing conventions, eligibility rules, and provider calculations can differ. Use figures from your official quote, statement, contract, or tax form before making a financial decision.
Which inputs have the biggest effect on the result?+
Rate, time, starting balance, recurring payments or contributions, and fees usually have the largest effects. Change one input at a time to create a conservative, expected, and optimistic scenario instead of relying on a single forecast.
Are taxes, fees, and inflation included?+
Only when they appear as an input or are explicitly described in the methodology. Do not assume an omitted cost is zero. Review the formula and methodology sections to see exactly what is included before comparing the result with an outside quote.
Can this calculator predict future rates or returns?+
No. A calculator projects the assumptions entered; it cannot predict market returns, inflation, variable interest rates, tax-law changes, or provider decisions. Rerun the calculation with several assumptions to understand the range of possible outcomes.
Why might my lender, bank, broker, or tax software show a different result?+
Professional systems may use daily timing, transaction dates, compounding conventions, rounding rules, account-specific fees, credits, eligibility details, or regulations that a general-purpose calculator cannot know. A small difference can be rounding; a large difference usually means an assumption or included cost is different.
Disclaimer: Calculations are for informational purposes only and do not constitute professional financial advice. Please consult with a certified professional before making financial decisions.