Tax
Self-Employment Tax Calculator
Estimate the Social Security and Medicare tax on your 1099 or side-hustle income, and what to set aside.
Figures below use 2025 tax year numbers — a Social Security wage base of $176,100. These change every year, so confirm the current-year figures before you file.
What this means
On $60,000 in net profit, this comes out to about $8,478 in self-employment tax — $6,871 for Social Security and $1,607 for Medicare. You can deduct $4,239 of that against your income tax.
This is self-employment tax only — it doesn’t include federal or state income tax on the same profit, and it’s an estimate, not tax advice. A common habit: set aside 25% to 30% of every payment for taxes as it comes in, so the bill is already covered when it’s due.
Build on it
These are estimates to help you think — not personalized legal, tax, or investment advice, and not a promise of any result. In the app, Brix reads your numbers and turns them into your next step.
This calculator estimates the self-employment tax on your 1099 or side-hustle profit — the Social Security and Medicare tax that isn't automatically taken out the way it is from a paycheck. Enter your net profit and it shows the Social Security portion, the Medicare portion, and what you can deduct at tax time.
Why it matters: when you work for someone else, they pay half of your Social Security and Medicare tax without you noticing. When you're self-employed, you pay both halves — 15.3% combined on most of your profit — and nobody withholds it for you. Knowing the number before the IRS tells you means it never has to be a surprise.
How to use it
- 1
Enter your net profit
Use your self-employment profit — income minus your business expenses — not your gross revenue. That's the number the IRS actually taxes.
- 2
Add any W-2 wages
If you also have a day job, enter the wages where Social Security was already withheld. That amount can fill up the Social Security wage base before your side income even gets there, which changes what you owe.
- 3
Pick your filing status and read the result
Filing status only matters for the Additional Medicare surtax, which kicks in above a set income level. The result shows each piece of the tax, the total, and the half you get to deduct from your income tax.
Behind the numbers
The 92.35% adjustment
Self-employment tax isn't charged on your full profit — the law reduces it to 92.35% first, roughly accounting for the employer-equivalent share a W-2 worker's boss would normally cover. That haircut happens automatically in the calculator, the same way it does on Schedule SE.
Two taxes, two different caps
The Social Security portion (12.4%) only applies up to a wage base that changes every year — earn more than that between wages and self-employment combined, and the extra isn't taxed for Social Security. The Medicare portion (2.9%) has no cap at all, and above a set income level an extra 0.9% Additional Medicare surtax kicks in on top.
Why half is deductible
A W-2 employer's share of Social Security and Medicare is deductible to them as a business expense — so the law lets self-employed people deduct half of their SE tax too, to keep things roughly even. That deduction lowers your income tax, not your SE tax; you still owe the full amount.
The math behind it
Self-employment tax runs on 92.35% of your net profit — the “net earnings” figure. Social Security takes 12.4% of that, but only up to the year's wage base (and any W-2 wages use up that base first). Medicare takes 2.9% with no cap, plus another 0.9% on net earnings above a threshold set by your filing status. Add the pieces together for the total.
Worked example
$60,000 in net profit, no W-2 job, filing single: net earnings are $55,410. Social Security is 12.4% of that — about $6,871. Medicare is 2.9% — about $1,607. Total self-employment tax: roughly $8,478, of which about $4,239 is deductible against income tax.
Set aside 25–30%
A working rule of thumb: bank 25% to 30% of every 1099 payment for taxes — self-employment tax plus income tax — the moment it lands. Adjust up if you're in a higher income tax bracket, down if you're not. Setting it aside as you're paid beats scrambling to find it in April.
Common questions
How much self-employment tax will I owe?
Roughly 15.3% of 92.35% of your net profit, split between Social Security (12.4%, up to the year's wage base) and Medicare (2.9%, no cap) — plus an extra 0.9% on income above the Additional Medicare threshold. The calculator runs your real numbers through each piece.
Do I owe self-employment tax if I also have a W-2 job?
Only on the portion of your combined income that hasn't already used up the Social Security wage base. If your day job wages already exceed that base, your side income only owes the Medicare portion — the calculator accounts for this when you enter your W-2 wages.
Is any of this deductible?
Half of your self-employment tax is deductible against your income tax — not your SE tax itself, which you owe in full. The Additional Medicare surtax, if it applies, is never deductible. A tax professional can confirm how this fits into your full return.
Go deeper
The calculator gives you a number. The Taxes Brick teaches you what to do with it, in plain English. And if you’re not sure where to start, the free BrickScore checks your whole foundation in about 5 minutes.