Who has to pay self-employment tax?
Generally, you owe self-employment tax if your net earnings from self-employment were $400 or more during the tax year. This includes income from freelancing, consulting, gig-economy driving or delivery work, single-member LLCs taxed as sole proprietorships, and general partnership income allocated to you.
It does not typically apply to wages you receive as a W-2 employee, since your employer already withholds and matches Social Security and Medicare taxes on that income. If you have both W-2 wages and self-employment income in the same year, the Social Security wage base is applied across both sources combined, not separately.
What are the self-employment tax rates and wage base for 2026?
Self-employment tax combines two components: a 12.4% Social Security portion and a 2.9% Medicare portion, for a combined 15.3% rate. The Social Security portion only applies up to an annual wage base limit that is adjusted for inflation each year; the Medicare portion has no upper income limit.
In addition, an Additional Medicare Tax of 0.9% applies to self-employment income above set thresholds based on filing status. This additional tax is not split or deductible the way the base self-employment tax is.
| Component | Rate | Income limit |
|---|---|---|
| Social Security portion | 12.4% | Applies up to the annual Social Security wage base (inflation-adjusted for 2026) |
| Medicare portion | 2.9% | No income limit — applies to all net self-employment earnings |
| Additional Medicare Tax | 0.9% | Applies above filing-status thresholds (e.g., single vs. married filing jointly) |
| Combined base rate | 15.3% | 12.4% + 2.9%, before Additional Medicare Tax |
How is this calculated? What formula does the calculator use?
How is this calculated? Taxcentra's self-employment tax calculator follows the same method used on IRS Schedule SE for the 2026 tax year. First, it takes your net self-employment income (gross self-employment revenue minus ordinary and necessary business expenses).
Second, it multiplies that net income by 92.35% to get your net earnings from self-employment. This 92.35% adjustment exists because self-employment tax itself is not taxed again, roughly approximating the effect of an employer's matching share not being included in taxable wages.
Third, it applies 12.4% to the portion of those net earnings up to the Social Security wage base, and 2.9% to all net earnings for Medicare, adding the 0.9% Additional Medicare Tax if your income exceeds the relevant threshold. Finally, the calculator notes that half of your total self-employment tax (excluding the Additional Medicare Tax) is deductible as an adjustment to income on your Form 1040, which reduces your income tax, though not your self-employment tax itself.
Can I deduct any part of my self-employment tax?
Yes. You can deduct one-half of your self-employment tax as an above-the-line deduction when calculating your adjusted gross income, even if you don't itemize deductions. This deduction reflects the portion that would have been paid by an employer if you were a traditional employee.
This deduction lowers your income tax liability but does not reduce the amount of self-employment tax you actually owe. It's a separate benefit meant to partially offset the fact that self-employed individuals pay both the 'employer' and 'employee' shares themselves.
How do quarterly estimated taxes relate to self-employment tax?
Because no employer withholds tax from self-employment income, the IRS generally expects self-employed individuals to make quarterly estimated tax payments covering both income tax and self-employment tax if they expect to owe $1,000 or more for the year.
Estimated payments are typically due four times per year. Underpaying can result in an estimated tax penalty even if you pay the full balance by the filing deadline, so many self-employed workers use a calculator like this one throughout the year to adjust their quarterly payment amounts as income fluctuates.
| Quarter | Typical due period | Purpose |
|---|---|---|
| Q1 | Income earned Jan–Mar | Covers income + SE tax on first quarter earnings |
| Q2 | Income earned Apr–May | Adjust for income changes since Q1 |
| Q3 | Income earned Jun–Aug | Mid-year reconciliation of projected liability |
| Q4 | Income earned Sep–Dec | Final estimate before year-end filing |
Does an S-corp election reduce self-employment tax?
Some business owners elect S-corporation taxation specifically because reasonable W-2 wages paid to themselves are subject to standard payroll tax, while remaining profit distributions are not subject to self-employment tax. This can reduce overall self-employment/payroll tax liability in some situations.
This strategy involves additional payroll administration, reasonable-compensation rules enforced by the IRS, and other tradeoffs that vary by business size and profitability. It's a decision best made with a licensed tax professional or CPA rather than based solely on a calculator estimate.
What business expenses reduce my self-employment tax?
Any ordinary and necessary business expense that reduces your net self-employment income will proportionally reduce your self-employment tax, since the tax is calculated on net earnings, not gross revenue. Common deductible expenses include home office costs, business mileage, equipment, software subscriptions, professional services, and health insurance premiums (though the health insurance deduction affects income tax, not self-employment tax directly).
Keeping organized records of business expenses throughout the year, rather than trying to reconstruct them at tax time, generally leads to more accurate net income figures and a more reliable self-employment tax estimate.
What happens if I have both a job and self-employment income?
If you earn W-2 wages and also have self-employment income, your employer's withholding already counts toward the Social Security wage base. The self-employment tax calculation accounts for wages already subject to Social Security tax when determining how much of your self-employment income is still subject to the 12.4% portion.
The Medicare portion (2.9%) and Additional Medicare Tax (0.9% above the threshold) still generally apply to all self-employment earnings regardless of W-2 wages, since Medicare tax has no wage base cap.