What Is Self-Employment Tax?

When you work as a W-2 employee, your employer pays half of your FICA taxes (Social Security + Medicare = 7.65%) while you pay the other half through withholding. As a self-employed person, sole proprietor, or 1099 contractor, there is no employer — so you pay both halves: 15.3% of net self-employment income up to the Social Security wage cap ($176,100 in 2026), then 2.9% above that for Medicare only.

Self-employment tax is paid in addition to regular income tax — it's a common shock for people first going freelance who underestimate their total tax burden.

Calculating Your Net Self-Employment Income

SE tax applies to your net profit, not gross revenue. Net profit = total revenue minus ordinary business expenses. If you earned $100,000 in freelance income but had $25,000 in legitimate deductible expenses (software, equipment, home office, professional development), your SE tax is calculated on $75,000 — not $100,000. Tracking expenses meticulously is essential to minimizing SE tax legally.

The Half-Deduction Offset

The IRS allows you to deduct half of your SE tax from your adjusted gross income before calculating income tax. This partially offsets the double-FICA burden. If your SE tax is $10,600 (15.3% × $69,281), you can deduct $5,300 from your gross income before applying income tax brackets. This brings your effective total tax rate closer to what a W-2 employee pays on the same earnings.

QBI deduction: Many self-employed individuals also qualify for the 20% Qualified Business Income (QBI) deduction under Section 199A. This can reduce taxable income by up to 20% of net self-employment income. Income limits and profession restrictions apply — consult a tax professional for complex situations.

Quarterly Estimated Tax Payments

Unlike W-2 employees who have taxes withheld from every paycheck, self-employed workers must pay taxes themselves on a quarterly schedule. The 2026 deadlines are: April 15 (Q1), June 16 (Q2), September 15 (Q3), and January 15, 2027 (Q4). Each payment covers both SE tax and income tax for that quarter.

Underpaying by more than $1,000 from your actual tax liability (or paying less than 90% of current-year tax, or less than 100% of last year's tax) results in an underpayment penalty. A practical rule of thumb: set aside 25–30% of every client payment immediately into a tax savings account.

Key Deductible Business Expenses

Legitimate business expenses reduce your taxable net profit and therefore reduce both SE tax and income tax: home office deduction (dedicated workspace — either actual expenses or $5/sq ft, up to 300 sq ft), equipment and technology, software subscriptions, professional services (accountant, attorney), marketing and advertising, professional development and education, health insurance premiums (deductible as an above-the-line deduction from gross income), and retirement contributions (SEP-IRA allows contributions up to 25% of net earnings or $69,000 in 2026).

Retirement Savings as a Tax Strategy

A SEP-IRA is the most powerful tax-reduction tool for self-employed individuals. Unlike a 401(k) limit of $23,500, a SEP-IRA allows contributions up to 25% of net self-employment income (after the SE tax deduction), with a 2026 maximum of $69,000. Every dollar contributed reduces your taxable income dollar-for-dollar. A freelancer earning $120,000 could contribute ~$22,000 to a SEP-IRA, saving $6,000–$8,000 in combined federal income and SE taxes while building retirement assets.