Self-Employment Tax Calculator 2025

How Self-Employment Tax Works

Self-employment (SE) tax is the 15.3% combined Social Security and Medicare tax that freelancers, independent contractors, sole proprietors, and gig workers pay — the same two programs funded by FICA payroll taxes for traditional W-2 employees. The critical difference is that W-2 employees split FICA with their employer (each side pays 7.65%), while self-employed individuals pay the full 15.3% themselves because they are both employer and employee.

The 15.3% rate breaks down into two components: 12.4% for Social Security (Old-Age, Survivors, and Disability Insurance) and 2.9% for Medicare (Hospital Insurance). Social Security tax applies only up to an annual wage base cap, which is $168,600 for 2025. Any net SE earnings above that cap are exempt from the Social Security portion but still subject to the 2.9% Medicare tax, which has no cap. High earners face an additional 0.9% Medicare surtax on earnings exceeding $200,000 for single filers ($250,000 for married filing jointly), bringing the Medicare rate to 3.8% on income above the threshold.

You must pay self-employment tax if your net self-employment earnings are $400 or more per year. This applies regardless of your age — even if you are already collecting Social Security benefits. SE tax is reported on Schedule SE (Form 1040) and is in addition to your regular federal and state income taxes.

Self-Employment Tax Calculation Steps

The SE tax calculation follows a specific multi-step formula. Here is how it works, illustrated with a $100,000 net income example:

Step 1: Determine net self-employment income. Start with your gross self-employment revenue and subtract all allowable business expenses (reported on Schedule C). For our example, assume net income is $100,000.

Step 2: Multiply by 92.35%. The IRS only taxes 92.35% of your net SE income, not the full amount. This adjustment mirrors the fact that employers pay half of FICA and that employer portion is not considered taxable income for the employee. $100,000 x 0.9235 = $92,350 in taxable SE earnings.

Step 3: Calculate Social Security tax. Apply the 12.4% rate to taxable SE earnings up to the wage base cap. $92,350 x 0.124 = $11,451.40 in Social Security tax.

Step 4: Calculate Medicare tax. Apply the 2.9% rate to all taxable SE earnings (no cap). $92,350 x 0.029 = $2,678.15 in Medicare tax. Since $92,350 is below the $200,000 Additional Medicare Tax threshold, no surtax applies.

Step 5: Add them up. $11,451.40 + $2,678.15 = $14,129.55 total self-employment tax.

Step 6: Calculate the deductible half. You can deduct 50% of your SE tax ($7,064.78) as an above-the-line adjustment on your income tax return. This reduces your adjusted gross income (AGI) and therefore your income tax liability. This deduction is taken on Schedule 1 of Form 1040 and does not require itemizing.

Effective rate: On $100,000 of net income, the $14,129.55 in SE tax represents an effective rate of 14.13%. After factoring in the income tax savings from the 50% deduction, the real after-tax cost is lower.

Key Self-Employment Tax Terms

Schedule SE (Form 1040) is the IRS form used to calculate self-employment tax. It takes your net SE earnings from Schedule C (or Schedule K-1 for partnerships) and walks through the calculation to arrive at your total SE tax. The result flows to Schedule 2 of your Form 1040.

Net Earnings from Self-Employment is your gross self-employment income minus allowable business expenses. This is the starting point for the SE tax calculation. It comes from line 31 of Schedule C (for sole proprietors) or your share of partnership income from Schedule K-1.

Qualified Business Income (QBI) Deduction allows eligible self-employed individuals to deduct up to 20% of their qualified business income from their taxable income. This is a separate deduction from the SE tax deduction and applies only to income tax, not to self-employment tax. The QBI deduction phases out for specified service trades at higher income levels ($191,950 single, $383,900 married filing jointly for 2025).

Estimated Quarterly Payments are prepayments of both income tax and self-employment tax made four times per year using Form 1040-ES. Due dates are April 15, June 15, September 15, and January 15 of the following year. You must make estimated payments if you expect to owe $1,000 or more in total tax. The safe harbor rule protects you from penalties if you pay at least 100% of your prior-year tax (110% if your AGI exceeded $150,000).

Self-Employed vs. W-2 Employee: Tax Comparison

Understanding how SE tax compares to W-2 employment taxes helps you plan your finances accurately. The table below compares the two scenarios for a worker earning $100,000.

While self-employed workers pay more in payroll-type taxes, they gain access to business expense deductions, the QBI deduction, and flexible retirement plans that can significantly reduce their overall tax burden compared to a W-2 employee at the same income level.

Practical Examples

Example 1 — Freelance graphic designer: Lisa earns $75,000 in net self-employment income after deducting $15,000 in business expenses from her $90,000 gross revenue. Her taxable SE earnings are $75,000 x 0.9235 = $69,263. Social Security tax: $69,263 x 0.124 = $8,589. Medicare tax: $69,263 x 0.029 = $2,009. Total SE tax: $10,598. Deductible half: $5,299. Lisa's effective SE tax rate on her $75,000 net income is 14.13%. She should also set aside money for federal income tax on her remaining taxable income after the SE deduction and standard deduction.

Example 2 — Rideshare driver (gig worker): Marcus drives for a rideshare platform and earns $45,000 in gross fares. After deducting $12,000 in vehicle expenses (mileage at $0.70/mile), phone costs, and platform fees, his net SE income is $33,000. Taxable SE earnings: $33,000 x 0.9235 = $30,476. Social Security: $30,476 x 0.124 = $3,779. Medicare: $30,476 x 0.029 = $884. Total SE tax: $4,663. Deductible half: $2,332. Marcus's effective SE rate is 14.13%. Because his income is relatively modest, he may also qualify for the Earned Income Tax Credit, which could offset a portion of his income tax.

Example 3 — High-earning consultant: Priya earns $280,000 in net consulting income. Taxable SE earnings: $280,000 x 0.9235 = $258,580. Social Security tax applies only up to the $168,600 wage base: $168,600 x 0.124 = $20,906. Medicare tax on all earnings: $258,580 x 0.029 = $7,499. Additional Medicare Tax on earnings above $200,000: ($258,580 - $200,000) x 0.009 = $527. Total SE tax: $20,906 + $7,499 + $527 = $28,932. Deductible half: $14,466. Priya's effective SE rate is 10.33% — lower than the standard 14.13% because the Social Security cap means a smaller percentage of her total income is subject to the 12.4% rate.

Tax-Saving Strategies for Self-Employed Individuals

Contribute to a SEP-IRA or Solo 401(k). Self-employed individuals have access to powerful retirement plans that can shelter significant income from income tax (though not from SE tax). A SEP-IRA allows contributions of up to 25% of net self-employment earnings (after the SE deduction), with a maximum of $69,000 for 2025. A Solo 401(k) offers similar limits but also allows employee elective deferrals of up to $23,500 ($31,000 if age 50+), plus employer profit-sharing contributions. These contributions reduce your AGI and income tax liability while building retirement savings. Use our 401(k) calculator to model contribution scenarios.

Deduct health insurance premiums. If you are self-employed and not eligible for an employer-sponsored plan (including through a spouse), you can deduct 100% of your health insurance premiums for yourself, your spouse, and your dependents as an above-the-line deduction. This includes medical, dental, and qualifying long-term care insurance. The deduction cannot exceed your net SE income and is taken on Schedule 1 of Form 1040.

Claim the home office deduction. If you use a dedicated space in your home regularly and exclusively for business, you can deduct a portion of your rent or mortgage interest, utilities, insurance, and repairs. The simplified method allows $5 per square foot up to 300 square feet ($1,500 maximum). The regular method calculates actual expenses based on the percentage of your home used for business. Either method reduces your Schedule C income and therefore your SE tax base.

Maximize business expense deductions. Every legitimate business expense you deduct on Schedule C reduces both your income tax and your self-employment tax. Common deductions include equipment and software, professional development and courses, business travel, office supplies, marketing and advertising costs, professional services (accounting, legal), and business insurance. Keep detailed records and receipts for every expense.

Pay estimated taxes on time. While this does not reduce your tax, it prevents costly underpayment penalties. Use Form 1040-ES and make payments by the quarterly deadlines (April 15, June 15, September 15, January 15). The IRS charges interest on underpayments at the federal short-term rate plus 3 percentage points. Use our quarterly tax calculator to estimate your payments.

Consider your business structure. Operating as a sole proprietor means all net income is subject to SE tax. If your business earns significantly more than a reasonable salary, forming an S-corporation may allow you to pay yourself a reasonable salary (subject to FICA) and take the remaining profit as a distribution (not subject to SE tax). However, S-corp election involves additional compliance costs including payroll processing, corporate tax returns, and reasonable compensation analysis. Consult a CPA to determine if the tax savings justify the added complexity for your specific situation.