How to Calculate Self-Employment Tax (2026 Guide)

The formula (memorize this)

SE Tax = Net Business Profit × 0.9235 × 15.3%

That's it for most people. The two tricky parts:

• The 92.35% adjustment (0.9235) — accounts for the fact that you can deduct half of SE tax, so you only pay SE on 92.35% of your profit
• The Social Security wage base cap — only the 2.9% Medicare portion continues after profit exceeds the 2026 cap of $176,100

Step-by-step

Step 1: Calculate net business profit

Net profit = Gross revenue minus business expenses. This is the number on line 31 of your Schedule C.

Example: You earned $75,000 gross from freelance design. Business expenses (software, home office %, equipment) were $12,000. Net profit = $63,000.

Step 2: Multiply by 92.35%

$63,000 × 0.9235 = $58,180.50

This is your "net earnings from self-employment" — the base for SE tax calculation.

Step 3: Apply the 15.3% rate

$58,180.50 × 15.3% = $8,901.62

This is your SE tax — the amount that goes on Schedule SE and transfers to line 23 of your 1040.

Step 4: Deduct half as an above-the-line adjustment

$8,901.62 / 2 = $4,450.81

This reduces your AGI on Schedule 1 line 15. You still paid the full $8,901.62 in SE tax — but you don't pay regular income tax on the deductible half.

Worked examples

Example 1: Side-hustle freelancer ($50,000 net profit)

• Net earnings: $50,000 × 0.9235 = $46,175
• SE tax: $46,175 × 15.3% = $7,064.78
• Deductible half: $3,532.39

Example 2: Full-time freelancer ($100,000 net profit)

• Net earnings: $100,000 × 0.9235 = $92,350
• SE tax: $92,350 × 15.3% = $14,129.55
• Deductible half: $7,064.77

Example 3: High-earner ($200,000 net profit — wage base cap applies)

At this income, you hit the 2026 Social Security wage base cap of $176,100. Above that, only 2.9% Medicare continues.

• Net earnings: $200,000 × 0.9235 = $184,700
• Social Security portion: $176,100 × 12.4% = $21,836.40
• Medicare portion (all of net earnings): $184,700 × 2.9% = $5,356.30
• SE tax: $27,192.70
• Deductible half: $13,596.35

The Additional Medicare Tax (over $200k / $250k)

If your total income (W-2 + self-employment) exceeds:

• $200,000 (single / HoH)
• $250,000 (married filing jointly)
• $125,000 (married filing separately)

You owe an additional 0.9% Medicare tax on the excess. This is calculated on Form 8959 and added to your total tax. Not technically part of SE tax, but it hits self-employment income.

Common mistakes

• Forgetting the 92.35% adjustment — people calculate 15.3% × full profit and overpay by ~$800 on a $50k profit
• Not tracking quarterly estimates — SE tax is supposed to be paid throughout the year
• Missing the wage base cap — high-earners shouldn't pay 15.3% on income above $176,100 Social Security wage base
• Not reducing income tax for the SE deduction — half of SE tax is deductible against ordinary income
• Paying SE tax on W-2 income — SE tax only applies to business profit, not wages where FICA is already withheld

SE tax + income tax: the combined impact

A common eye-opener for new freelancers: your total tax is SE tax + federal income tax + state tax. At $75,000 net profit, single filer:

• SE tax: ~$10,594
• Federal income tax (after SE deduction): ~$8,200 (roughly 22% bracket)
• State tax (varies): $0-$5,500 depending on state
• Total tax: $18,800 - $24,300 (25-32% of gross)

This is why gig workers and freelancers typically need to set aside 25-30% of their gross for taxes — a huge adjustment from W-2 thinking where it's 15-20%.

How to pay

File Schedule SE along with your 1040. Pay through:

• Quarterly estimated taxes (Form 1040-ES or IRS Direct Pay) — the correct way
• Increased withholding from a W-2 job (if you also have one) via Step 4(a) on your W-4
• Lump sum at tax filing — allowed, but if you owe $1,000+ you'll pay underpayment penalty