Self-Employment Tax Calculator
Calculate the Social Security and Medicare tax you owe on net earnings from freelancing, contracting, or 1099 income — including the Additional Medicare Tax, the 50% SE tax deduction, and quarterly payment estimates for 2025 and 2026.
How Self-Employment Tax Works
When you're an employee, Social Security and Medicare tax (FICA) is split evenly between you and your employer — 7.65% each, for a combined 15.3%. As a self-employed person, there's no employer to split the bill with, so you pay the full 15.3% yourself through self-employment (SE) tax: 12.4% for Social Security and 2.9% for Medicare.
The 92.35% Net Earnings Adjustment
SE tax isn't calculated on your full net profit. The IRS first multiplies your net profit by 92.35% to get your "net earnings from self-employment" — a rough proxy for the fact that an employer's matching FICA contribution is never itself taxed. That adjusted figure is what gets taxed at 15.3%.
The Social Security Wage Base
The 12.4% Social Security portion only applies up to an annual wage base: $176,100 for 2025 and $184,500 for 2026. Earnings above that cap escape the Social Security portion entirely — though the 2.9% Medicare portion keeps applying with no cap at all. If you also have a W-2 job, your wages and SE income share one combined wage base.
Additional Medicare Tax for High Earners
On top of the regular 2.9% Medicare tax, an extra 0.9% Additional Medicare Tax applies to combined wages and SE earnings above $200,000 (single, head of household), $250,000 (married filing jointly), or $125,000 (married filing separately). These thresholds are fixed by law and don't adjust for inflation, so they apply unchanged in 2025 and 2026.
The Self-Employment Tax Deduction
As partial relief, you can deduct 50% of your SE tax — the 15.3% portion only — as an above-the-line deduction on Schedule 1 when calculating your adjusted gross income. This mirrors the fact that an employer's half of FICA is never taxable income to an employee. It reduces your income tax, but it does not reduce the SE tax bill itself, and it doesn't apply to the 0.9% Additional Medicare Tax.
Quarterly Estimated Tax Payments
If you expect to owe $1,000 or more for the year, the IRS expects you to pay as you go, in four estimated installments generally due April 15, June 15, September 15, and January 15 of the following year. Missing a payment can trigger an underpayment penalty even if you pay everything in full by the filing deadline.
Frequently Asked Questions
What is the self-employment tax rate for 2025 and 2026?
The rate is 15.3% in both years — 12.4% for Social Security and 2.9% for Medicare. The rate itself doesn't change; what changes is the Social Security wage base, rising from $176,100 in 2025 to $184,500 in 2026.
How is self-employment tax actually calculated?
Take your net profit, multiply by 92.35%, then apply 12.4% Social Security (up to the wage base) and 2.9% Medicare (no cap) to that figure. High earners add a further 0.9% Additional Medicare Tax above their filing-status threshold.
Do I owe self-employment tax if I also have a W-2 job?
Yes, but your W-2 wages and SE income share one combined Social Security wage base. If your W-2 wages already used up the year's wage base, the 12.4% Social Security portion no longer applies to your SE earnings — only the 2.9% Medicare portion does. The Additional Medicare Tax threshold is shared the same way.
Can I deduct self-employment tax?
Yes — you can deduct 50% of the 15.3% portion as an above-the-line deduction on Schedule 1. This lowers your adjusted gross income and therefore your income tax, but it does not reduce the SE tax bill itself, and it never applies to the 0.9% Additional Medicare Tax.
When are quarterly estimated tax payments due?
Generally April 15, June 15, September 15, and January 15 of the following year — shifting to the next business day if one falls on a weekend or holiday. You need to make estimated payments if you expect to owe $1,000 or more for the year.
Do I owe self-employment tax on a small side income?
Only if your net earnings from self-employment — net profit after the 92.35% adjustment — are $400 or more for the year. Below that, no SE tax is owed, though the income may still need to be reported for income tax purposes.