Self-Employment Tax Calculator
Use our self employment tax calculator to get instant, accurate results. This free self employment tax calculator makes complex calculations simple and fast. First year freelancing and you're about to learn what 15.3% self-employment tax plus federal income tax plus state tax feels like. Spoiler: it's 35-50% of your profit. Let's calculate how much to set aside so April doesn't destroy you.
Your Business Income
Tax Breakdown (Self Employment Tax Calculator)
💰 Quarterly Estimated Tax Payments
Per Quarter (pay 4 times/year):
Deadlines: April 15, June 15, Sept 15, Jan 15
Set aside 0% of every payment you receive
Self-Employment Tax: The Double FICA Hit (Self Employment Tax Calculator)
W-2 employees pay 7.65% FICA (Social Security 6.2% + Medicare 1.45%). Employers pay the other 7.65%. Total: 15.3%, split 50/50. Self-employed? You pay BOTH halves. All 15.3%. On top of regular income tax. This is the tax nobody warns you about.
💡 Expert Tips
New freelancer, first April: bloodbath. Client made $95k her first year, spent it all ("I'll deal with taxes later"). April 15: owed $14k SE tax + $16k income tax + $4.5k state = $34,500 total. Had $8k saved. Went on IRS payment plan at 8% interest. Took 18 months to pay off, cost her $2,700 in interest/penalties. Rule #1: Set aside 35% of EVERY payment the day you receive it. Transfer to separate savings account. Pretend it doesn't exist. This is not your money—it's the IRS's.
The SE Tax Formula
SE Tax = Net Profit × 92.35% × 15.3%
Why 92.35%? IRS gives you a deduction for half the SE tax you pay (employers get to deduct their 7.65% as a business expense, so you get an equivalent deduction). It's automatic—you don't have to do anything special.
Example:
- Gross income: $100,000
- Business expenses: -$15,000
- Net profit: $85,000
- SE taxable amount: $85k × 92.35% = $78,498
- SE tax: $78,498 × 15.3% = $12,010
That $12k is ON TOP OF income tax. If you're in the 22% federal bracket, you owe ~$16k income tax + $12k SE tax + state tax. Total: $30k-35k on $85k profit.
⚠️ Common Mistake: "I'll Just Pay Taxes in April"
IRS requires quarterly estimated payments if you'll owe >$1,000. Don't pay quarterly? Underpayment penalty: 3-8% of the shortfall. Example: Owe $28k total, paid $0 quarterly. Penalty: ~$1,500-2,000. Plus you're scrambling to find $28k in one month. Pay quarterly or Die April trying. Many people blow their tax refund on a vacation, then owe $25k the next year with no cushion. Ugly cycle.
Quarterly Estimated Tax Deadlines
Four payments per year:
- Q1 (Jan 1 - Mar 31): Due April 15
- Q2 (Apr 1 - May 31): Due June 15
- Q3 (Jun 1 - Aug 31): Due September 15
- Q4 (Sep 1 - Dec 31): Due January 15 (next year)
Notice Q2 is only 2 months and Q3 is 3 months. IRS logic makes zero sense. Just mark your calendar.
How to pay:
- Online: IRS.gov/payments (free, instant)
- Form 1040-ES: Mail a check (slow, risky)
- EFTPS.gov: Set up auto-pay (best for consistency)
What You CAN Deduct (Before SE Tax)
Reduce your net profit = lower SE tax. Legit deductions:
- Home office: Simplified method = $5/sq ft, up to 300 sq ft = $1,500 max. Or actual expenses (% of rent, utilities).
- Equipment: Laptop, desk, monitor, phone (business use only)
- Software/subscriptions: Adobe, Figma, Slack, website hosting
- Mileage: $0.67/mile (2024 rate) for business driving (NOT commuting to office you rent)
- Health insurance: Premiums are deducted on Form 1040 (separate from Schedule C), reduces income tax but not SE tax
- Marketing: Website, ads, business cards, networking events
- Professional fees: CPA ($500-2k), lawyer, software subscriptions
- Travel: Business trips (conferences, client meetings). Vacation mixed with work? Allocate % to business.
Example impact:
- $100k revenue - $20k legit expenses = $80k net profit
- SE tax on $80k: $11,316
- vs $100k net profit: SE tax $14,130
- Deductions save $2,814 in SE tax alone
Safe Harbor Rule: Avoid Penalties
Pay quarterly but still underpay? You're safe from penalties if you meet "Safe Harbor":
- Pay 100% of last year's total tax (110% if income >$150k)
- OR pay 90% of current year's tax
Example:
- 2024 tax bill: $25,000
- 2025 projected tax: $35,000
- If you pay $25k via quarterly payments (100% of prior year), no penalty even though you underpaid $10k
This is a lifesaver for volatile income—just match last year's number quarterly, deal with the difference in April.
Frequently Asked Questions
What is self-employment tax?
15.3% tax on net profit: 12.4% Social Security + 2.9% Medicare. W-2 employees pay half (7.65%), employer pays the other half. Self-employed pay BOTH halves. Calculated on 92.35% of net earnings (you get a small deduction). Example: $80k profit → $80k × 92.35% = $73,880 × 15.3% = $11,304 SE tax. This is ON TOP OF regular income tax (10-37% federal + state).
How do I pay quarterly estimated taxes?
IRS wants taxes paid as you earn. Four deadlines: Q1 (April 15), Q2 (June 15), Q3 (Sept 15), Q4 (Jan 15). Use Form 1040-ES or pay online at irs.gov/payments. Calculate: (Annual SE Tax + Income Tax + State Tax) ÷ 4. Example: Owe $25k total for year → $6,250 per quarter. Miss a payment? Underpayment penalty (3-5% on amount owed). Set aside 30-35% of every payment you receive.
Can I deduct business expenses?
YES. Deduct legitimate expenses from revenue BEFORE calculating SE tax. Common: home office (simplified $5/sq ft up to 300 sq ft), equipment/software, mileage ($0.67/mile 2024), health insurance premiums (deducted on 1040, not Schedule C), marketing, professional fees. Example: $100k revenue - $15k expenses = $85k net profit. SE tax on $85k, not $100k. Saves you $2,295 in SE tax alone. Keep receipts, use accounting software. Our Self Employment Tax Calculator makes this easy.
What happens if I don't pay quarterly?
Two bad outcomes: 1) Underpayment penalty: If you owe >$1,000 at tax time and didn't pay 90% during year, IRS charges 3-8% penalty on shortfall. 2) Massive April bill: Owe $20k-40k+ all at once, can't pay it, interest accrues monthly (currently 8%). Safe harbor: Pay 100% of last year's tax liability (110% if income >$150k) via quarterly payments = no penalty even if you underpaid. Use the Self Employment Tax Calculator above to verify.