Self-Employment Tax Calculator

1. Enter your net self-employment profit, that is income after business expenses.
2. If you also have a regular job, add the wages already taxed for Social Security.
3. Optionally set your rough federal income tax rate for the set-aside estimate.
4. Read your self-employment tax, quarterly payment and total to set aside.

Self-employment tax is the Social Security and Medicare tax paid by people who work for themselves. An employee splits these taxes with an employer, but a self-employed person pays both halves, which is why the combined rate is 15.3 percent: 12.4 percent for Social Security and 2.9 percent for Medicare.

It is charged on 92.35 percent of your net profit, not the full amount, because you can first deduct the employer-equivalent portion. It applies once your net self-employment earnings reach 400 dollars in a year.

1. Multiply your net profit by 0.9235 to get the taxable base.
2. Apply 12.4 percent Social Security up to the annual wage base, minus any wages already taxed at a job.
3. Apply 2.9 percent Medicare to the whole base, with no cap.
4. Add them for your SE tax; half of it is deductible against income tax.

Only the Social Security part is capped by the wage base. The Medicare part has no ceiling, and very high earners pay an extra 0.9 percent Medicare surtax not shown here.

Suppose your net profit is 60,000 dollars. Multiply by 0.9235 to get 55,410 dollars. Social Security at 12.4 percent is 6,871 dollars and Medicare at 2.9 percent is 1,607 dollars, so your self-employment tax is about 8,478 dollars. Half of that, roughly 4,239 dollars, lowers your income tax. Adding an estimated income tax puts your total set-aside near 25 to 30 percent of profit, or about 3,800 dollars per quarter.

Net Profit, Not Revenue

SE tax is based on profit after business expenses, so tracking and claiming every legitimate expense directly lowers the tax.

Wages from a Regular Job

Social Security wages you already earned at a W-2 job count toward the annual cap, so the Social Security part of your SE tax can shrink or disappear once you pass the wage base.

The Wage Base Cap

Only Social Security is capped at the annual wage base; Medicare applies to all profit, so above the cap your marginal SE rate drops from 15.3 percent to 2.9 percent.

These are two separate taxes you pay on the same profit, which trips up many new freelancers.

The quarterly estimated payment covers both, which is why setting aside only for SE tax leaves you short.

If You Expect to Owe 1,000 Dollars or More

The IRS generally expects quarterly estimated payments once you will owe at least 1,000 dollars for the year.

Four Times a Year

Payments are due in April, June, September and January. Missing them can bring an underpayment penalty even if you pay in full at filing.

Set Money Aside Each Time You Are Paid

Moving a set percentage to a separate account with every invoice makes the quarterly payment painless.

1. Saving Only for Income Tax

SE tax is on top of income tax. Budget for both or you will be short.

2. Using Revenue Instead of Profit

SE tax is on net profit, so subtract business expenses first.

3. Forgetting the Half Deduction

Half of your SE tax reduces your income tax; missing it overpays.

4. Skipping Quarterly Payments

Paying only at filing can trigger an underpayment penalty.

This tool applies the standard SE tax formula and rates. It is an estimate for planning, not tax advice, and the income tax figure depends on the rate you enter.

Self-employment tax is 15.3 percent, made up of 12.4 percent Social Security and 2.9 percent Medicare, charged on 92.35 percent of your net profit.

Multiply your net profit by 0.9235, then apply 12.4 percent Social Security up to the wage base and 2.9 percent Medicare with no cap. Add the two.

A common rule is 25 to 30 percent of net profit, which covers self-employment tax plus federal income tax. Higher earners should set aside more.

You generally must pay quarterly once you expect to owe at least 1,000 dollars for the year. Payments are due in April, June, September and January.

Yes. You can deduct one half of your self-employment tax when figuring your income tax, which lowers your overall bill.

Yes, both apply to the same profit. Self-employment tax funds Social Security and Medicare, while income tax is separate and based on your bracket.

Wages already taxed for Social Security at your job count toward the annual cap, so the Social Security part of your self-employment tax can be reduced or removed.

You owe self-employment tax once your net self-employment earnings reach 400 dollars in a year.

No. The calculator runs entirely in your browser and nothing you enter is stored or sent anywhere.

• IRS: self-employment tax (US Internal Revenue Service).
• IRS: estimated taxes (US Internal Revenue Service).
• Social Security wage base (Wikipedia).