Self-Employment Tax Calculator (US)

Enter your annual net profit as a US freelancer or sole proprietor to estimate your Self-Employment Tax under Schedule SE (12.4% Social Security + 2.9% Medicare), plus any Additional Medicare Tax and the deductible half.

What is the Self-Employment Tax Calculator?

This tool estimates the Self-Employment Tax that US freelancers and sole proprietors owe. Traditional employees split Social Security and Medicare tax (7.65% combined) with their employer, but the self-employed must pay the full 15.3% themselves — a burden that often catches new freelancers off guard.

Just enter your annual net profit (from Schedule C) and this tool automatically calculates your Social Security tax, Medicare tax, and any Additional Medicare Tax, along with the amount you can deduct on your income tax return (half of your SE tax). It is useful for estimating your tax bill before filing, or for sizing up quarterly estimated tax payments.

How to use it

Enter your annual net profit Enter the net profit from your Schedule C — income minus business expenses — in dollars.
Choose your filing status Select single, married filing jointly, or head of household. This changes the Additional Medicare Tax threshold.
Enter any W-2 wages already earned (optional) If you also have a day job already subject to Social Security tax, entering it makes the remaining wage-base calculation more accurate.
Check the results The total tax owed (Social Security + Medicare + Additional Medicare) and the deductible amount are calculated automatically.

Tips for getting more out of it

If your adjusted net earnings are below $400, you are not required to file Self-Employment Tax at all — worth checking if your side income is small.
If you also have a day job, Social Security tax room is used up by your W-2 wages first, which can reduce (or eliminate) the Social Security portion owed on your self-employment income.
Deducting half of your SE tax lowers your taxable income for income tax purposes — it does not reduce the SE tax itself.
If you expect to owe a meaningful amount in tax, skipping quarterly estimated tax payments can trigger an underpayment penalty.
This tool estimates federal tax only — check your state or local tax authority separately for any additional obligations.

When to use this

Estimating SE tax before filing

Once your annual net profit is finalized, get a rough tax figure before filling out Schedule SE.

Sizing quarterly estimated tax payments

Divide your estimated annual SE tax by four to get a starting point for quarterly estimated tax payments.

Checking your remaining Social Security room with a side hustle

If you already pay Social Security tax through a day job, see how much of your side income is still subject to it.

Planning before going full-time freelance

Before leaving a salaried job, estimate how much SE tax will cut into your take-home pay as a sole proprietor.

Glossary

Self-Employment Tax: The combined Social Security and Medicare tax (15.3%) paid by the self-employed. Employees split this with their employer; the self-employed pay the full amount themselves.
Schedule SE: The IRS form (attached to Form 1040) used to calculate Self-Employment Tax from your net profit.
92.35% adjustment: The factor applied to net self-employment profit before calculating SE tax, meant to approximate the employer-equivalent share that is excluded from the taxable base for employees.
Social Security Tax: A tax that funds future retirement benefits. The self-employed rate is 12.4%, but it only applies up to $184,500 (the 2026 wage base).
Medicare Tax: A tax that funds health coverage for seniors and people with disabilities. The self-employed rate is 2.9%, with no income cap.
Additional Medicare Tax: An extra 0.9% tax on higher earners, starting at $200,000 for single/head of household filers or $250,000 for married filing jointly.
SE Tax Deduction: A rule that lets you deduct half of your Self-Employment Tax from your adjusted gross income, easing the sense of double taxation.

Frequently Asked Questions

It isn't a higher rate — as a self-employed person, you pay the full 15.3% that an employee and employer would otherwise split between them. The total cost is roughly the same either way.

Only if your net earnings (after the 92.35% adjustment) are $400 or more. Below that, you are not required to file Self-Employment Tax.

Since Social Security tax only applies up to $184,500 (2026), if your W-2 wages already approach that limit, the Social Security portion owed on your self-employment income may be reduced or eliminated.

Yes. Self-employment tax is calculated separately on Schedule SE and paid alongside your regular income tax, though half of it can be deducted when calculating your taxable income.

Side Note — Why does self-employment tax look double the employee rate?

When you work as an employee, your paycheck shows 7.65% withheld for Social Security and Medicare combined. The moment you go freelance, that same system suddenly seems to double to 15.3% — and plenty of new freelancers are caught off guard by it. The rate itself hasn't changed; what changed is that the half your employer used to quietly cover is now a bill you see and pay directly.

This split exists because Social Security and Medicare were designed around shared employer-employee contributions. As an employee, your pay stub only shows your half, but your employer is paying an equal amount behind the scenes — so the real cost is roughly the same whether you're salaried or self-employed. The difference is that the self-employed write one check for the whole amount, which makes the burden much more visible.

To soften that "double burden" feeling, the tax code lets you deduct half of your Self-Employment Tax from your adjusted gross income. Even so, many freelancers only realize the size of the bill when tax season arrives, so estimating it ahead of time matters for cash flow planning. Missing quarterly estimated payments can also trigger penalties, which is one more reason to run the numbers early.

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