Guide · 9 min read · Updated 2025

    Self-employment tax, explained

    The 15.3% bill every freelancer, 1099 contractor, and gig worker owes — what it is, how to calculate it, and how to legally pay less.

    The short version

    When you work for yourself, no employer is covering the Social Security and Medicare half of your payroll taxes. You pay both halves: 15.3% of your net earnings. That's on top of regular federal and state income tax.

    Quick math: Earn $80,000 net from freelance work? Roughly $11,300 SE tax + ~$10,000 federal income tax + state. Total tax bill: ~$22–26k. Save 30% of every check.

    The exact formula

    1. Net earnings = gross revenue − all business expenses (home office, software, mileage, etc.)
    2. SE-tax base = net earnings × 92.35% (you're allowed to subtract the "employer half" first)
    3. SE tax owed = SE-tax base × 15.3% (up to the Social Security wage cap, then 2.9% above)
    4. Income tax deduction = half of SE tax reduces your taxable income for regular federal tax

    2025 thresholds you need

    $400 — minimum SE income before owing SE tax
    $176,100 — Social Security wage cap (2025)
    15.3% — combined SS + Medicare rate
    12.4% — Social Security portion
    2.9% — Medicare portion (no cap)
    0.9% — extra Medicare surtax above $200k single
    $1,000 — owe more than this → quarterly payments
    Apr 15 / Jun 15 / Sep 15 / Jan 15 — quarterly due dates

    5 legal ways to lower your SE tax

    1. 1

      Track every business expense

      The single biggest lever. Every $1,000 in expenses = ~$153 less SE tax + ~$220 less income tax. Software, home office, mileage, phone, internet, equipment, professional fees, education.

    2. 2

      Take the home office deduction

      Regular and exclusive use of part of your home for business. Simplified: $5/sq ft up to 300 sq ft = $1,500 max. Actual: % of home × (rent/mortgage + utilities + insurance). Often the bigger one.

    3. 3

      Elect S-corp once profit reliably exceeds ~$60–80k

      Pay yourself a reasonable salary (W-2, owes FICA) and take the rest as distributions (no SE tax). Savings start at $2–4k/yr, scale up fast. Costs ~$500–1,500/yr in compliance overhead.

    4. 4

      Max a SEP-IRA or Solo 401(k)

      SEP: up to ~20% of net SE earnings. Solo 401(k): $23,000 employee + 25% employer share. These cut income tax dramatically. They don't cut SE tax — but a lower tax bill is a lower tax bill.

    5. 5

      Pay quarterly to avoid penalties

      Underpayment penalty is small but annoying — interest on the missed amount. Paying quarterly also smooths cash flow and forces you to know your numbers.

    Know your number, automatically

    SnapBooks tracks net income, flags deductible expenses, and shows your quarterly tax estimate in real time.

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    Frequently asked questions

    What is self-employment tax?+

    Self-employment (SE) tax covers Social Security (12.4%) and Medicare (2.9%) for people who work for themselves. The combined rate is 15.3% on the first $168,600 of net earnings (2024 wage base; rises to $176,100 for 2025), plus 2.9% Medicare on everything above. High earners pay an extra 0.9% Medicare surtax above $200k single / $250k joint.

    Who has to pay self-employment tax?+

    Anyone with $400+ in net self-employment income in a year: freelancers, 1099 contractors, sole proprietors, single-member LLC owners, gig workers (Uber, DoorDash, Instacart), and partners in partnerships. W-2 employees don't pay SE tax — their employer covers half via FICA.

    How is self-employment tax calculated?+

    Take net earnings (revenue minus business expenses), multiply by 92.35% to get your SE-tax base, then multiply by 15.3%. Example: $50,000 net × 0.9235 = $46,175 × 0.153 = $7,065 SE tax. Half of that ($3,532) is deductible against your income tax.

    How is SE tax different from income tax?+

    They're two separate bills on the same dollars. SE tax is a flat 15.3% (Social Security + Medicare). Income tax is your bracket (10–37% federal, plus state). A freelancer netting $80k owes roughly $11k SE tax PLUS regular income tax on top.

    Can I lower my self-employment tax?+

    Yes: (1) deduct every legitimate business expense to lower net earnings, (2) form an S-corp once profit reliably exceeds ~$60–80k and pay yourself a reasonable salary (only the salary owes FICA, not the distributions), (3) contribute to a SEP-IRA or Solo 401(k) — these lower income tax but NOT SE tax.

    When is self-employment tax due?+

    Quarterly: April 15, June 15, September 15, and January 15 of the following year. If you'll owe more than $1,000 total, the IRS expects estimated payments. Miss them and you'll owe an underpayment penalty even if you pay in full by April 15.