Self-Employment Tax Calculator
Enter your net self-employment income to instantly calculate SE tax (15.3%), the Social Security and Medicare breakdown, the deductible half of SE tax, estimated income tax, and quarterly estimated payment amounts - with the 2025 Social Security wage cap ($176,100) and Additional Medicare Tax applied automatically.
SE Tax Calculator Auto Year
️ Disclaimer: Estimates only. Consult a CPA or tax professional for your specific situation.
SE Tax Rates Current Year
| Component | Rate | Wage Base / Limit |
|---|
Federal Income Tax Brackets
| Rate | Single | Married Filing Jointly |
|---|
Quarterly Due Dates
| Quarter | Income Period | Due Date |
|---|---|---|
| Q1 | Jan 1 – Mar 31 | April 15 |
| Q2 | Apr 1 – May 31 | June 16 |
| Q3 | Jun 1 – Aug 31 | September 15 |
| Q4 | Sep 1 – Dec 31 | January 15 (next year) |
How Self-Employment Tax Works
What is Self-Employment Tax?
When you're an employee, your employer pays half of Social Security (6.2%) and Medicare (1.45%) taxes - you pay the other half. When self-employed, you pay BOTH halves - that's the SE tax. The IRS lets you deduct half of it to partially offset the burden.
Step 1 - Net Earnings Subject to SE Tax
SE Tax Base = Net SE Income × 92.35%
(= multiplying by 0.9235)
Why 92.35%? Because the deductible half of SE tax
(7.65%) is subtracted first. This mirrors how employees
don't pay FICA on the employer's matching share.
Step 2 - Calculate SE Tax
(only on first $176,100 in 2025)
Medicare = SE Tax Base × 2.9%
(no wage base limit)
Additional Medicare = 0.9% on SE income over
$200,000 (single) or $250,000 (MFJ)
SE Tax Total = Social Security + Medicare + Add'l Medicare
Step 3 - Deductible Half of SE Tax
This deduction reduces your Adjusted Gross Income (AGI),
which in turn reduces your federal income tax.
It is an "above-the-line" deduction - you don't need
to itemize to claim it.
Step 4 - Adjusted Gross Income (AGI)
− Deductible Half of SE Tax
− Self-Employed Health Insurance
− SEP-IRA / Solo 401k Contributions
− Home Office Deduction
− Other Business Deductions
+ Other W-2 Income
Step 5 - Estimated Federal Income Tax
2025 Standard Deductions:
Single / MFS: $15,000
MFJ: $30,000
HOH: $22,500
Federal Income Tax = Apply progressive brackets to
Taxable Income
Step 6 - Total Tax Burden
Effective Total Rate = Total Tax ÷ Net SE Income
Important: SE tax is paid IN ADDITION to income tax.
This is why self-employed individuals often pay more
total tax than employees at the same income level.
Frequently Asked Questions
Self-Employment Tax Calculator 2025 - How SE Tax Works and What You Actually Owe
Self-employment tax is one of the most frequently misunderstood aspects of freelancing and running a business. Many new freelancers set aside 20–25% for taxes and then get a surprise when their actual bill is higher. Understanding the structure - that you pay FICA taxes at the employee AND employer rate - is essential for accurate financial planning.
The SE Tax Breakdown - Social Security + Medicare
Social Security (12.4%)
- Rate: 12.4% - combines employee 6.2% + employer 6.2%
- 2025 wage cap: $176,100 of net SE income
- Above $176,100: NO additional Social Security tax owed
- Wage base increases annually with wage inflation
- Max SS tax 2025: $176,100 × 0.9235 × 0.124 = $20,130
Medicare (2.9% + 0.9%)
- Base Medicare rate: 2.9% - no income cap. All SE income taxed.
- Additional Medicare Tax: +0.9% on SE income over $200,000 (single) or $250,000 (MFJ)
- The 0.9% AMT is not matched by any employer - entirely self-paid
- At $250K net SE income: $200K at 2.9% + $50K at 3.8% = $7,700 Medicare tax
- Medicare provides future health coverage - not just a tax
Why 92.35%? - The Math Behind the SE Tax Base
When an employee earns $100,000, they pay 6.2% SS + 1.45% Medicare = 7.65% ($7,650). Their employer also pays 7.65% - but the employee never sees that money. Total FICA: $15,300.
For self-employed individuals: you pay the full 15.3%, but the IRS lets you deduct the "employer equivalent" half (7.65%) before calculating the tax. Instead of computing this exactly, the IRS uses the approximation: multiply net income × 0.9235 (which = 1 − 0.0765) as the tax base. This produces essentially the same result and mirrors the employee experience.
The actual computation: $100,000 × 0.9235 = $92,350. $92,350 × 15.3% = $14,130. If you calculated 7.65% on $100,000 = $7,650 deduction, then ($100,000 − $7,650) × 15.3% = $14,122 - virtually identical.
Quarterly Estimated Taxes - 2025 Due Dates and Safe Harbour
Self-employed individuals typically don't have taxes withheld - you must pay estimated taxes quarterly to avoid IRS underpayment penalties. The 2025 payment schedule:
- Q1 (January 1 – March 31): Due April 15, 2025
- Q2 (April 1 – May 31): Due June 16, 2025
- Q3 (June 1 – August 31): Due September 15, 2025
- Q4 (September 1 – December 31): Due January 15, 2026
To avoid penalties, pay the lesser of: (a) 90% of your current year estimated total tax, or (b) 100% of your prior year's total tax (110% if prior year AGI exceeded $150,000). This is called the "safe harbour" rule - if you meet either threshold, no underpayment penalty applies even if you owe more at filing.
How this calculator works, and where the numbers come from
The Self Employment Tax applies the standard formula for this calculation to the values you enter and updates the result as you type. The calculation itself happens in your browser, and the page explains the method so you can check any result by hand.
Please note: Tax rules change and depend on your personal situation. Results are estimates, not tax advice. Confirm current rates and rules with the official tax authority or a qualified tax professional.
Sources and further reading
Learn more
Read our guide: Marginal vs Effective Tax Rate: Why a Raise Never Costs You