Data Notice: Tax figures in this article reflect 2026 IRS rules. The Social Security wage base, tax rates, and thresholds are subject to annual inflation adjustments. Confirm current figures at IRS.gov. [self-employment-tax-calculation-step-by-step]

How to Calculate Self-Employment Tax Step by Step

Tax information in this article is for educational purposes only and does not constitute tax, legal, or financial advice. Tax laws change frequently, and individual circumstances vary. Consult a qualified tax professional or CPA for guidance specific to your situation.

Self-employment tax is the 15.3% tax that freelancers, independent contractors, and sole proprietors pay to cover Social Security and Medicare. Unlike W-2 employees who split these taxes with their employer, self-employed individuals pay both halves. This guide walks through the exact calculation with worked examples at multiple income levels.

The Self-Employment Tax Formula

The basic formula has five steps:

Start with net self-employment income (Schedule C profit)
Multiply by 92.35% (the taxable portion)
Apply the 12.4% Social Security rate (up to the wage base)
Apply the 2.9% Medicare rate (no cap)
Add the 0.9% Additional Medicare Tax (if applicable)

2026 Key Numbers

Component	Rate	Limit
Social Security	12.4%	First $184,500 of SE earnings
Medicare	2.9%	No limit
Additional Medicare	0.9%	Over $200,000 single / $250,000 MFJ
Combined SE Tax	15.3%	Up to SS wage base
92.35% factor	Applied to net SE income	Accounts for employer-equivalent deduction

Worked Example 1: Freelancer Earning $60,000

Step 1: Net self-employment income = $60,000

Step 2: Taxable SE income = $60,000 × 0.9235 = $55,410

Step 3: Social Security tax = $55,410 × 12.4% = $6,870.84

Step 4: Medicare tax = $55,410 × 2.9% = $1,606.89

Step 5: Additional Medicare Tax = $0 (income below $200,000 threshold)

Total SE tax = $6,870.84 + $1,606.89 = $8,477.73

Deductible half = $8,477.73 ÷ 2 = $4,238.87 (above-the-line deduction on Form 1040)

Worked Example 2: Freelancer Earning $120,000

Step 1: Net self-employment income = $120,000

Step 2: Taxable SE income = $120,000 × 0.9235 = $110,820

Step 3: Social Security tax = $110,820 × 12.4% = $13,741.68

Step 4: Medicare tax = $110,820 × 2.9% = $3,213.78

Step 5: Additional Medicare Tax = $0 (income below $200,000 threshold)

Total SE tax = $13,741.68 + $3,213.78 = $16,955.46

Deductible half = $16,955.46 ÷ 2 = $8,477.73

Worked Example 3: High-Earning Freelancer at $250,000

Step 1: Net self-employment income = $250,000

Step 2: Taxable SE income = $250,000 × 0.9235 = $230,875

Step 3: Social Security tax = $184,500 × 12.4% = $22,878.00 (capped at wage base)

Step 4: Medicare tax = $230,875 × 2.9% = $6,695.38

Step 5: Additional Medicare Tax = ($230,875 − $200,000) × 0.9% = $277.88

Total SE tax = $22,878.00 + $6,695.38 + $277.88 = $29,851.26

Deductible half = ($22,878.00 + $6,695.38) ÷ 2 = $14,786.69

Note: The Additional Medicare Tax ($277.88) is not deductible. Only the base 15.3% SE tax qualifies for the half-deduction.

Why the 92.35% Factor Exists

The 92.35% multiplier (100% minus 7.65%) simulates what an employer would pay. When you have an employer, they pay 7.65% of your wages toward FICA. That employer portion is not part of your taxable wages. The 92.35% factor gives self-employed individuals the same treatment — it reduces the base before applying the 15.3% rate.

The Half-of-SE-Tax Deduction

You deduct half of your self-employment tax as an above-the-line deduction on Schedule 1 of Form 1040. This deduction:

Reduces your adjusted gross income (AGI)
Lowers your federal income tax
Is available whether you itemize or take the standard deduction
Does not reduce your SE tax itself (it only reduces income tax)

This deduction mirrors the fact that employers deduct their FICA contributions as a business expense.

SE Tax When You Also Have W-2 Income

If you have both W-2 wages and self-employment income, the Social Security wage base is shared. Your employer already withholds Social Security tax on your W-2 wages. You only pay the 12.4% Social Security portion of SE tax on the gap between your W-2 wages and the $184,500 wage base.

Example: You earn $140,000 in W-2 wages and $60,000 in net self-employment income.

W-2 wages already covered: $140,000 of the $184,500 SS wage base
Remaining SS wage base: $184,500 − $140,000 = $44,500
SE taxable income: $60,000 × 0.9235 = $55,410
SS tax on SE income: $44,500 × 12.4% = $5,518.00 (limited to remaining base)
Medicare on SE income: $55,410 × 2.9% = $1,606.89
Total SE tax: $7,124.89

For the full picture on handling both types of income, see Part-Time Freelance Side Hustle Taxes: W-2 Plus 1099.

Strategies to Reduce Self-Employment Tax

1. Maximize Business Deductions

Every dollar of business expense reduces your Schedule C profit, which reduces your SE tax base. See Every Tax Deduction Freelancers Can Claim in 2026.

2. S-Corp Election

By electing S-Corp status, you pay yourself a reasonable salary (subject to payroll taxes) and take remaining profits as distributions (not subject to SE tax). See S-Corp Election for Freelancers.

3. Retirement Contributions

While retirement contributions do not directly reduce SE tax, they reduce your income tax. A Solo 401(k) allows up to $72,000 in combined contributions. See SEP IRA vs Solo 401(k) for Freelancers.

4. Hire Your Spouse

If your spouse works in your business, their wages are subject to FICA but may allow access to employer-sponsored benefit plans, potentially reducing overall family tax burden.

Quick Reference: SE Tax at Various Income Levels

Net SE Income	SE Tax	Effective SE Rate	Deductible Half
$30,000	$4,239	14.13%	$2,120
$50,000	$7,065	14.13%	$3,533
$75,000	$10,597	14.13%	$5,299
$100,000	$14,130	14.13%	$7,065
$150,000	$21,194	14.13%	$10,597
$200,000	$27,198	13.60%	$13,599
$250,000	$29,851	11.94%	$14,787

The effective rate drops above the Social Security wage base because the 12.4% SS tax no longer applies.

Key Takeaways

Self-employment tax is 15.3% on 92.35% of net SE income
Social Security tax (12.4%) caps at $184,500 in 2026 earnings
Medicare tax (2.9%) has no cap; an extra 0.9% applies above $200,000
You deduct half of SE tax as an above-the-line deduction, reducing income tax
W-2 wages reduce the remaining Social Security wage base available for SE income
S-Corp election and maximized deductions are the primary strategies for reducing SE tax

For a complete overview of freelance tax obligations, see our Complete Guide to Freelance Taxes in 2026.

Sources

Self-Employment Tax — Internal Revenue Service — accessed March 28, 2026
Topic No. 554, Self-Employment Tax — Internal Revenue Service — accessed March 28, 2026
Topic No. 751, Social Security and Medicare Withholding Rates — Internal Revenue Service — accessed March 28, 2026
IRS Releases Tax Inflation Adjustments for Tax Year 2026 — Internal Revenue Service — accessed March 28, 2026