Self-Employment Tax Calculator — 2025 SE Tax (15.3%)
Estimate your 2025 self-employment tax on 1099 or freelance net profit — the 15.3% SE rate, Social Security wage base, and half-SE deduction. In your browser.
About Self-Employment Tax Calculator
A self-employment tax calculator is a tool that estimates the Social Security and Medicare tax you owe on freelance, contractor, or other 1099 net profit for the 2025 tax year. Self-employment (SE) tax is charged at 15.3% on 92.35% of your net profit: 12.4% for Social Security up to the 2025 wage base of $176,100, plus 2.9% for Medicare with no ceiling. Higher earners add a 0.9% Additional Medicare Tax above $200,000 (single), $250,000 (married filing jointly), or $125,000 (married filing separately). Half of the base SE tax is deductible against your income tax. It runs entirely in your browser and is an estimate, not tax advice.
Use cases
- Estimate what a 1099 year really costs. Employees split Social Security and Medicare with their employer, but as a self-employed person you pay both halves yourself, which is why the SE rate feels high. Entering your expected net profit shows the SE tax alone, separate from income tax, so you can see the true payroll-tax cost of freelancing and set aside a realistic amount before the money is spent.
- Set money aside from each payment. Because no employer withholds tax from a contractor cheque, it is easy to under-save and face a large bill at filing time. Multiplying a rough SE rate against each invoice as it arrives helps you park the right share in a separate account. Use this estimate to pick a percentage of every payment to hold back for the Social Security and Medicare portion.
- Account for a W-2 job alongside freelancing. If you also draw a regular paycheck, the Social Security wages already taxed there use up part of the $176,100 base, so less of your freelance profit is subject to the 12.4% Social Security piece — though the 2.9% Medicare part still applies to all of it. Entering your W-2 Social Security wages lets the estimate reduce the remaining wage base accordingly.
- See the value of the half-SE deduction. Half of your base SE tax can be subtracted from income before income tax is figured, softening the overall bite. Seeing that deduction spelled out helps you understand why the headline 15.3% is not the whole story, and reminds you to claim it when you file so you do not overpay your income tax on the same earnings.
- Compare a contract to a salaried role. When weighing a freelance contract against employment, the SE tax changes the real take-home comparison. Running your expected net profit through the calculator shows the Social Security and Medicare cost you would carry alone, so you can compare a contract rate against a salaried job on a more honest, after-payroll-tax basis rather than headline pay.
How it works
- Enter your net profit. Type your expected 2025 self-employment net profit — gross income minus deductible business expenses — which is the figure SE tax is based on.
- Choose your filing status. Select single, married filing jointly, or married filing separately so the correct Additional Medicare threshold is applied.
- Add any W-2 Social Security wages. If you also have a job, enter its Social Security wages so the tool subtracts them from the $176,100 base before charging the 12.4% part.
- Let it apply the 92.35% factor. The calculator multiplies your net profit by 0.9235, then applies 12.4% Social Security up to the wage base and 2.9% Medicare with no cap.
- Read your SE tax and deduction. It shows total SE tax, any 0.9% Additional Medicare, and the deductible half you can claim against your income tax.
Examples
Input: Net profit $50,000, single, no W-2 job
Output: SE tax ≈ $7,065; half-SE deduction ≈ $3,532
$50,000 × 92.35% = $46,175 taxable, all below the wage base, so the full 15.3% applies.
Input: Net profit $200,000, single, no W-2 job
Output: SE tax ≈ $27,193; half-SE deduction ≈ $13,596
Only $176,100 of the $184,700 taxable base is hit by the 12.4% Social Security part; the 2.9% Medicare part covers all of it.
Input: Net profit $60,000 plus $150,000 W-2 Social Security wages
Output: Reduced Social Security portion; full Medicare still applies
The $150,000 of W-2 wages leaves only $26,100 of the base, so most freelance profit skips the 12.4% part but not the 2.9% Medicare.
Frequently asked questions
How is self-employment tax calculated?
Your net profit is first multiplied by 92.35% (0.9235). That amount is taxed at 12.4% for Social Security up to the 2025 wage base of $176,100 and at 2.9% for Medicare with no upper limit, for a combined 15.3% on earnings below the base.
What is the 92.35% factor for?
It reflects the employer-share deduction: because employees do not pay SE tax on their employer’s half, the self-employed reduce net profit by 7.65% before the tax applies, which works out to multiplying by 0.9235.
What is the Additional Medicare Tax?
An extra 0.9% Medicare tax on earnings above $200,000 (single), $250,000 (married filing jointly), or $125,000 (married filing separately). It applies on top of the regular 2.9% Medicare part for higher earners.
Does this include my income tax?
No. This tool estimates only Social Security and Medicare (SE) tax. It does not compute federal income tax, state tax, tax credits, or the Qualified Business Income (QBI) deduction — those are separate and can change what you actually owe.
How does a regular job affect my SE tax?
Social Security wages from a W-2 job count toward the same $176,100 base. If your job already used part or all of it, less of your self-employment profit is subject to the 12.4% Social Security portion, though the 2.9% Medicare portion still applies to all of it.
Can I deduct any of the SE tax?
Yes. Half of your base SE tax is an above-the-line deduction that lowers your taxable income for income-tax purposes. This estimate shows that deductible half so you can remember to claim it when you file.
Is this tax advice?
No. It is a 2025 (TY2025) educational estimate for US federal SE tax and can differ from your final return. For decisions about your taxes, consult a qualified tax professional or the IRS instructions for Schedule SE.
Pro tips
- Base the estimate on net profit — gross income minus business expenses — not your gross revenue.
- Set aside a share of each payment as it arrives, since no employer withholds SE tax for you.
- Remember to claim the half-SE deduction at filing so you do not overpay your income tax.
- Enter W-2 Social Security wages if you also have a job, or the Social Security part may be overstated.
- Pair this with a separate income-tax and QBI estimate — SE tax is only one piece of what you owe.
Reviewed by Ahsan Mahmood · Last updated 2026-07-08 · Part of ZTools.
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