US Self-Employment Tax Calculator

US Self-Employment Tax Guide

What is Self-Employment Tax?

Self-employment tax is the freelancer/sole proprietor equivalent of FICA payroll taxes that W-2 employees pay. Rate: 15.3% of net self-employment earnings (technically 15.3% × 92.35% of net earnings = effective 14.13%). Components: Social Security 12.4% on income up to $176,100 (2025 wage base). Medicare 2.9% on all income with no cap. Additional 0.9% Medicare surtax on SE income over $200,000 (single) / $250,000 (married). Why the higher rate vs W-2 workers? W-2 employees pay 7.65% and their employer pays the other 7.65% on their behalf, whereas the self-employed must cover both halves themselves.

What should I know about Deductions That Reduce Tax?

Several deductions specifically help self-employed: (1) Half of SE tax deductible from income for federal income tax purposes (above-the-line deduction). (2) Self-employed health insurance premiums fully deductible (avoiding the 7.5% AGI medical expense threshold). (3) SEP IRA or Solo 401(k) contributions — Solo 401(k) allows up to $23,500 employee + 25% of net SE earnings as employer contribution (combined max $70,000 for 2025). (4) Home office deduction — Simplified method: $5 per square foot up to $1,500 maximum, a much easier calculation than tracking actual home expenses proportionally, though sometimes worth less than the actual-expense method.

What do I need to know about S Corp Election — The Biggest Tax Saving?

Sole proprietors/single-member LLCs can elect S Corporation taxation (Form 2553). Key benefit: only your SALARY is subject to SE tax. Distributions are NOT subject to SE tax. Example: $120,000 net self-employment income. As sole prop: $120k × 15.3% = $18,360 SE tax. As S Corp paying yourself $70k 'reasonable salary' + $50k distribution: only $70k × 15.3% = $10,710 SE tax. Saving: $7,650/year. Costs of S Corp: payroll service ($500-1,500/year), separate tax return Form 1120-S, must pay yourself a reasonable salary through payroll before taking any additional profit as a distribution.

What's the key thing to understand about Quarterly Estimated Taxes?

Self-employed people must pay quarterly estimated taxes — the IRS doesn't wait until April. Due dates: April 15, June 15, September 15, January 15 (of following year). Penalty for underpayment: typically the federal short-term rate + 3% on the underpayment amount, prorated. Safe harbor rule: avoid penalty by paying either 90% of current year's tax OR 100% of last year's tax (110% if AGI > $150,000). Calculate annual estimated tax, divide by 4, pay each quarter. Most freelancers underestimate Year 1 tax liability specifically, since there's no employer withholding to build the habit of setting money aside automatically.

How Is Self-Employment Tax Different From Payroll Tax?

When you work as a W-2 employee, your employer pays half of your Social Security and Medicare tax and withholds your half from your paycheck. When you're self-employed, there's no employer splitting that bill, so the IRS requires you to pay both halves yourself through self-employment tax (SE tax). The combined rate is 15.3% — 12.4% for Social Security (up to the annual wage base limit) and 2.9% for Medicare (with no cap, plus an Additional Medicare Tax above a threshold for high earners). Before applying that rate, the IRS lets you reduce your net profit by 7.65% first, which approximates the "employer half" an employee's company would never have reported as the worker's own income. You also get to deduct half of your SE tax as an adjustment to income on your federal return, which softens the blow even though it doesn't reduce the SE tax itself.

Why Do Freelancers Need to Pay Quarterly Estimated Taxes?

Because no employer withholds tax from a freelancer's income, the IRS expects self-employed workers to estimate their full-year tax liability — income tax plus self-employment tax — and pay it in four installments across the year rather than in one lump sum the following April. Miss this and you can owe an underpayment penalty even if you pay your full balance by the filing deadline, because the penalty is calculated on being late throughout the year, not just at year-end. A common rule of thumb is to set aside 25-30% of net self-employment income for combined federal tax and SE tax, adjusted up or down based on your actual tax bracket and state tax rules. This calculator's self-employment tax figure is the foundation for that quarterly estimate: add your expected income tax on top of it to size each payment.

The Deduction That Softens the Self-Employment Tax Hit

<p>One feature that eases the burden of self-employment tax is that the IRS lets you deduct half of what you pay in self-employment tax as an adjustment to your gross income when calculating your income tax, even if you don't itemize. The logic mirrors how an employer's half of FICA taxes is never counted as income to an employee in the first place — since a self-employed person is effectively paying both the employee and employer shares, the deduction puts them on more comparable footing. It doesn't reduce the self-employment tax itself, which is still calculated on the full net earnings figure, but it does lower the income subject to federal (and often state) income tax. This deduction is taken automatically when self-employment tax is calculated on Schedule SE and flows through to the income tax return, so most tax software applies it without extra input, but it's worth understanding why the two numbers — self-employment tax owed and the income tax savings from this deduction — move in opposite directions.</p>

Worked Example: Calculating Self-Employment Tax Step by Step

Take a freelancer with $100,000 in net self-employment earnings (business revenue minus business expenses) for the year. The IRS first requires multiplying net earnings by 92.35% before applying the SE tax rate — this adjustment exists because the employer-equivalent half of FICA taxes a W-2 worker's company pays is never itself subject to further FICA tax, so self-employed filers get an equivalent haircut applied to their earnings base before the tax rate is calculated. $100,000 × 92.35% gives a net earnings base of $92,350. The Social Security portion (12.4%) applies to that base up to an annual wage base cap that rises most years (recently in the $170,000-plus range) — since $92,350 sits comfortably under any recent cap, the full amount is taxed: $92,350 × 12.4% = $11,451.40. The Medicare portion (2.9%) has no cap at all, so it applies to the full $92,350: $92,350 × 2.9% = $2,678.15.

This freelancer also gets to deduct half of that $14,129.55 (about $7,065) as an above-the-line adjustment to income on Schedule 1 when calculating federal income tax — reducing taxable income without changing the SE tax figure itself, which is calculated separately on Schedule SE and added to the total tax bill. If net self-employment income were high enough to push combined earnings above roughly $200,000 (single filers) or $250,000 (married filing jointly) — thresholds set by statute and not indexed for inflation — an additional 0.9% Medicare surtax would apply to the portion above that threshold, stacking on top of the standard 2.9% Medicare rate with no equivalent deduction available for the surtax portion.

The Safe Harbor Rule for Quarterly Estimated Taxes

Because no employer withholds tax on self-employment income, the IRS expects quarterly estimated payments covering both income tax and self-employment tax, and it charges an underpayment penalty — calculated similarly to interest, based on the federal short-term rate plus a few percentage points — on any shortfall for each quarter it existed. The 'safe harbor' rules exist to give filers a target that guarantees no penalty regardless of how the current year actually turns out: paying at least 90% of the current year's eventual total tax liability across the four quarterly payments, or alternatively paying at least 100% of the prior year's total tax liability (rising to 110% of the prior year's liability for filers whose adjusted gross income exceeded a threshold, commonly $150,000, in the prior year), satisfies the safe harbor either way.

The prior-year 100%/110% route is generally the simplest for freelancers with unpredictable income, since it only requires knowing last year's completed tax return rather than forecasting a year still in progress — though if income grows substantially year over year, paying only the prior-year safe harbor amount avoids a penalty but can still leave a large final balance due in April, so it's worth setting aside extra cash even when technically safe-harbored.