How is self-employment tax calculated?
Self-employment (SE) tax is 15.3% of your net earnings — but it's not applied to your gross income. The IRS uses a slightly counterintuitive formula:
- Start with net earnings. Gross income minus business expenses.
- Multiply by 92.35%. This is the "SE tax base." (The math reflects that as a self-employed person, you can't deduct the employer half of FICA before applying SE tax to the same money.)
- Multiply by 15.3%. That's your SE tax. (Or 2.9% Medicare-only on amounts above the Social Security wage base of $176,100 for 2024.)
The 50% SE tax deduction: Half of the SE tax you pay is deductible from your income tax. The calculator above already accounts for this — it's why your federal tax estimate is lower than a simple bracket multiplication would suggest.
2025 federal income tax brackets
The federal income tax piece uses progressive brackets. Each "slice" of income is taxed at the bracket rate:
| Rate | Single | Married filing jointly |
|---|---|---|
| 10% | $0–$11,925 | $0–$23,850 |
| 12% | $11,925–$48,475 | $23,850–$96,950 |
| 22% | $48,475–$103,350 | $96,950–$206,700 |
| 24% | $103,350–$197,300 | $206,700–$394,600 |
| 32% | $197,300–$250,525 | $394,600–$501,050 |
| 35% | $250,525–$626,350 | $501,050–$751,600 |
| 37% | $626,350+ | $751,600+ |
Most self-employed workers fall in the 12% or 22% bracket. The standard deduction ($15,000 single / $30,000 MFJ for 2025) is subtracted before brackets are applied.
Common ways to reduce self-employment tax
1. Track every deduction
Every dollar of legitimate business expense lowers your net earnings and directly lowers SE tax. Common deductions self-employed people miss: home office, business mileage, software subscriptions, phone (business-use portion), internet, professional services, banking fees.
2. Consider an S-corp at higher incomes
Once your net self-employment income exceeds roughly $60,000–80,000, an S-corporation election can save real money on SE tax. You pay yourself a "reasonable salary" (subject to FICA) and take the remaining profit as distributions (not subject to FICA). The savings need to outweigh the added complexity (payroll, separate tax return), but at higher incomes the math is favorable.
3. Use retirement accounts
SEP-IRA, Solo 401(k), and similar retirement accounts let you contribute pre-tax dollars from self-employment earnings. The contribution lowers your taxable income (income tax savings) but does not reduce SE tax — it's still calculated on pre-retirement-contribution earnings.
4. Maximize the qualified business income (QBI) deduction
If your net business income qualifies, you may deduct up to 20% of it under the QBI deduction (Section 199A). Phases out at higher incomes for certain professions. This applies to income tax, not SE tax.
Quarterly estimated taxes
If you'll owe more than $1,000 in federal tax for the year, the IRS expects you to pay quarterly. Skipping these results in underpayment penalties. The four deadlines:
- April 15 — for income earned Jan–Mar
- June 15 — for income earned Apr–May
- September 15 — for income earned Jun–Aug
- January 15 — for income earned Sep–Dec
You can pay at IRS.gov/payments in about 10 minutes. The simplest approach: take your estimated annual tax and divide by 4.
This calculator is an estimate. Real tax outcomes depend on credits, deductions, retirement contributions, dependents, and other factors not captured here. For a personalized analysis specific to your hustle, state, and situation, run the free SideHustleGuard check below.
What counts as self-employment income?
SE tax applies to net earnings from any trade or business you operate as a sole proprietor, independent contractor, or gig worker. In practice, this means:
- Included: 1099-NEC and 1099-K income, cash payments from clients, tips you receive directly, income from selling handmade goods (Etsy, craft fairs), gig platform earnings (DoorDash, Uber, TaskRabbit, Rover), freelance project fees, consulting, coaching
- Not included for SE tax: W-2 wages (your employer handles FICA), investment income, rental income (unless you're a real estate dealer), Social Security benefits, unemployment compensation
Note that gross income from platforms isn't always your net SE income. Etsy sellers subtract cost of goods, shipping, Etsy fees, and materials. Drivers subtract the standard mileage rate. Freelancers subtract software, home office, and professional expenses. The calculator above uses your entered expenses to compute the correct net earnings.
Self-employment tax at a glance — by income level
Here's what a self-employed single filer with no other income owes at different net profit levels, after the standard deduction and the 50% SE tax deduction (2025 rates):
| Net SE profit | SE tax (15.3%) | Federal income tax | Total federal | Effective rate |
|---|---|---|---|---|
| $15,000 | $2,121 | $0 | $2,121 | 14.1% |
| $30,000 | $4,239 | $716 | $4,955 | 16.5% |
| $50,000 | $7,065 | $3,194 | $10,259 | 20.5% |
| $75,000 | $10,597 | $7,426 | $18,023 | 24.0% |
| $100,000 | $14,130 | $13,096 | $27,226 | 27.2% |
| $150,000 | $21,195 | $24,436 | $45,631 | 30.4% |
Estimates for single filers, 2025. Assumes standard deduction only, no other income, no retirement contributions. State taxes additional.
The practical takeaway: Most self-employed people in the $30k–$75k net profit range pay an effective federal rate of 16–24%. Setting aside 25–30% of every payment covers this for most people, with a small buffer for state taxes and any miscalculations.
State taxes on top of SE tax
SE tax is a federal obligation — but most states also tax self-employment income at the state level, using the same net profit figure. State rates vary significantly:
- No state income tax: Texas, Florida, Washington, Nevada, Wyoming, South Dakota, Alaska, Tennessee, New Hampshire (on most income)
- Low (under 4%): Indiana (3.05%), Michigan (4.25%), Pennsylvania (3.07%), Arizona (2.5%)
- Medium (5–6%): Most states, including Ohio, Virginia, Georgia, Colorado
- High (7–10%+): California (up to 13.3%), New York (up to 10.9%), New Jersey (up to 10.75%), Minnesota (9.85%), Oregon (9.9%)
California self-employed workers should budget closer to 35–40% total between federal SE tax, federal income tax, and California's state income tax. See the California self-employment tax guide for state-specific details.
Frequently asked questions
Do I have to pay self-employment tax?
Yes, if your net self-employment earnings are $400 or more in a year. SE tax covers Social Security and Medicare for self-employed people. There's no exemption based on age, having a day job, or being part-time.
How much should I set aside for self-employment taxes?
For most self-employed workers, set aside 25–30% of every payment in a separate account. This covers federal income tax (typically 10–22%), SE tax (15.3%), and most state taxes. Higher earners or high-tax states should aim closer to 35%.
Is half my SE tax really deductible?
Yes. Half of the SE tax you pay is deductible "above the line" from your gross income, lowering your federal income tax. This is the IRS's way of acknowledging that as a self-employed person, you're paying both the employee and employer halves of FICA.
Do I owe SE tax if I also have a W-2 job?
Yes. SE tax applies to self-employment income regardless of whether you also earn W-2 wages. Your employer handles FICA on your W-2 earnings, but side hustle income is entirely your responsibility. The only interaction: if your combined wages and SE income exceed the Social Security wage base ($176,100 for 2024), you stop owing the 12.4% Social Security portion on the overage — only the 2.9% Medicare tax continues.
Does age affect whether I owe SE tax?
No. SE tax has no age exemption. Even if you're collecting Social Security or Medicare, you still owe SE tax on self-employment earnings above $400. There's also no exemption for minors — a 16-year-old with a profitable Etsy shop technically owes SE tax. The only exception is certain religious order members and some nonresident aliens.
What happens to SE tax above the Social Security wage base?
The Social Security portion (12.4%) of SE tax only applies up to the annual wage base — $176,100 for 2024, adjusted each year for inflation. Above that threshold, you only owe the Medicare portion (2.9%), plus the 0.9% Additional Medicare Tax if total net earnings exceed $200,000 (single) or $250,000 (MFJ). So SE tax above the wage base is effectively 3.8% rather than 15.3%.