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Schedule SE

Self-Employment Tax Calculator

Working for yourself means paying both halves of Social Security and Medicare: 15.3% on 92.35% of your net profit, before a dollar of income tax is worked out. It is the charge that surprises first-year freelancers, and the one a W-2 job can partly absorb. Enter your profit to see what Schedule SE will ask for.

Sets the Additional Medicare threshold: $200,000 of earned income for this status.

Schedule C line 31 — gross income minus business expenses. Not your invoiced total.

Wages a job already withheld Social Security on. They share one wage base with your profit — $184,500 for 2026.

How Schedule SE gets there
Net profit
$90,000
Net earnings from self-employment (92.35% of profit)
The base the rates are charged on
$83,115
Social Security + Medicare (15.3%)
$12,717
Total self-employment tax
$12,717
Deducted on Schedule 1 (half of the regular charge)
Lowers income tax, not this tax. The extra Medicare is not deductible.
$6,358
Effective rate on your profit
14.1%
$12,717 of self-employment tax
That is 14.1% of your $90,000 profit, before any income tax. $6,358 of it comes back off your income on Schedule 1, which reduces income tax rather than this charge.
Walkthrough

Why the rate is what it is

An employee and an employer each pay half of Social Security and Medicare. Self-employed, you are both, so you pay the combined 15.3%: 12.4% Social Security and 2.9% Medicare.

Two adjustments stop that from being harsher than the employee version. First, the rates apply to 92.35% of net profit rather than all of it — the step that stands in for the employer half not being part of an employee's wages. Second, half of the resulting tax is deducted from your income before income tax is calculated.

The Social Security piece is capped. Once your net earnings plus any W-2 wages reach the year's wage base ($184,500), no more Social Security is charged for the year — which is why a second income source can leave a business profit facing 2.9% instead of the headline rate. Medicare never stops, and gains 0.9% above the Additional Medicare threshold.

What actually lowers this tax

  • Business expenses — the tax follows net profit, so every legitimate deduction on Schedule C lowers it as well as income tax. The home-office deduction is the one most sole proprietors leave on the table.
  • An S-corp election — splits the profit into a salary that carries payroll tax and distributions that do not. Whether that is worth the admin is a separate calculation: the S-corp calculator prices both sides.
  • Not retirement contributions — a Solo 401(k) deferral or a SEP contribution comes out after net earnings are fixed, so it cuts income tax and leaves this charge untouched. Same for the self-employed health insurance deduction.
  • Not the QBI deduction — §199A reduces taxable income, never net earnings. The QBI calculator shows what it is worth against income tax.
  • Paying on time — no one withholds this for you, so it is owed in quarterly instalments. The safe-harbor calculator works out the amount that switches the penalty off.
Questions

Frequently asked questions

How much is self-employment tax in 2026?
Self-employment tax is 15.3% — 12.4% Social Security plus 2.9% Medicare — and it is charged on 92.35% of your net profit, not on what you invoiced. The Social Security half stops once your net earnings plus any W-2 wages reach the wage base ($184,500 for 2026); the Medicare half has no ceiling, and an extra 0.9% is added on earned income above the Additional Medicare threshold for your filing status.
Is this on top of income tax?
Yes. Self-employment tax is the Social Security and Medicare contribution an employer and employee normally split — as your own employer you pay both halves — and it is charged whether or not you owe any income tax. Federal income tax is then calculated separately on your taxable income. The one offset is that half of the regular self-employment tax comes off your income on Schedule 1 before that second calculation.
Does a W-2 job reduce my self-employment tax?
Only the Social Security half, and only once your wages have used up the year's wage base ($184,500). Your employer already withheld Social Security on those wages, so the base left for your business profit is whatever is above them — the calculator takes the W-2 figure into account. Medicare is different: it applies to every dollar of net earnings no matter what your job paid, and the wages count toward the Additional Medicare threshold as well.
Do retirement contributions or the home-office deduction lower it?
A business expense does: self-employment tax is charged on net profit, so anything that legitimately lowers the profit — the home-office deduction, mileage, equipment, software — lowers this tax as well as income tax. Retirement contributions do not. A Solo 401(k) deferral, a SEP contribution and the self-employed health insurance deduction are all taken after net earnings are set, so they cut income tax and leave self-employment tax exactly where it was.
When do I actually pay it?
With your quarterly estimated payments, not in April. Self-employment tax is settled on Schedule SE with your return, but nobody is withholding it during the year, so the underpayment penalty runs from each quarterly due date. The safe-harbor calculator works out the minimum you have to send in to switch the penalty off.

See your full tax picture

Self-employment tax is one line of the bill. The full optimizer puts it beside income tax, the QBI deduction, entity choice, retirement room and any rental property — in one place, on your own numbers.

Open the full calculator

Last updated for tax year 2026 · Federal figures reviewed

Sources

  • Social Security wage base, 2026 — SSA annual wage-base announcement ($184,500)
  • Additional Medicare tax, 2026 — §3101(b)(2) — statutory thresholds, never indexed

Individual results vary. A planning estimate, not tax advice — confirm with a CPA before you file.

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