United States

Self-Employment Tax Calculator

Legal basis: IRC §1401 (self-employment tax); IRC §1402(b) (net earnings); Schedule SE (Form 1040); IRC §164(f) (deduction for one-half of SE tax) · checked 2026-10-04 · Rates and limits change — verify the current figures.

If you work for yourself — as a freelancer, independent contractor, gig worker, or sole proprietor — you do not receive a W-2, and no employer withholds Social Security and Medicare taxes from your pay. Instead, the Internal Revenue Code imposes self-employment (SE) tax directly on you under IRC §1401, and you report and pay it through Schedule SE attached to your Form 1040. SE tax is separate from, and in addition to, the income tax you owe on the same profit.

The calculation follows a fixed structure. First, net earnings from self-employment are computed by multiplying your net profit (usually from Schedule C) by 92.35% — this mirrors the employer's share that an employee never pays. Second, the Social Security portion, 12.4%, applies only up to a wage base that Congress adjusts almost every year; earnings above that base skip the Social Security tax entirely. Third, the Medicare portion, 2.9%, applies to all net earnings with no ceiling. If your combined wages and self-employment income are high enough, an additional 0.9% Medicare surtax applies to the excess above a threshold.

One important relief is built into the law: you may deduct one-half of your SE tax as an above-the-line adjustment to income under IRC §164(f). That deduction reduces your adjusted gross income even if you take the standard deduction and do not itemize. If you also have W-2 wages during the year, those wages count against the Social Security wage base first, which can reduce or eliminate the Social Security portion of your SE tax.

Because the Social Security wage base and the surtax threshold change with legislation and annual adjustments, this calculator treats them as editable inputs rather than fixed numbers. Enter the current-year figures from the Schedule SE instructions, and treat the result as an educational estimate — not tax advice — to confirm with the IRS instructions or a CPA before filing or making payments.

Calculate

Total self-employment taxSocial Security + Medicare portions$11,304

Net earnings (SE base)net profit × 92.35%$73,880

Social Security portion12.4% up to the wage base$9,161

Medicare portion2.9% with no ceiling$2,143

Additional Medicare tax0.9% above the threshold$0

Deductible half of SE taxabove-the-line adjustment (IRC §164(f))$5,652

Effective rate on net profit14.1%

How the math works

Net earnings from self-employment = net profit × 92.35% (IRC §1402(b)).
Social Security portion = 12.4% × net earnings up to the wage base (reduced by any W-2 wages already taxed).
Medicare portion = 2.9% × all net earnings, with no wage-base ceiling.
Additional Medicare tax = 0.9% × the excess of combined wages and net earnings over the surtax threshold.
One-half of the total SE tax is deductible as an adjustment to income under IRC §164(f).

Frequently asked questions

What is the self-employment tax rate?

The combined rate is 15.3% on net earnings up to the Social Security wage base: 12.4% for Social Security plus 2.9% for Medicare. Above the wage base only the 2.9% Medicare portion continues, and an additional 0.9% applies above a higher threshold. The wage base changes nearly every year, so check the current Schedule SE instructions.

Why is only 92.35% of my profit taxed?

Employees pay half of FICA and their employer pays the other half. Multiplying your net profit by 92.35% mimics removing the employer-equivalent share before applying the combined 15.3% rate, so the result approximates what an employee and employer would pay together on the same earnings.

Do I owe SE tax if I also have a W-2 job?

Yes, on your self-employment earnings, but your W-2 Social Security wages count against the wage base first. If your wages already reach or exceed the base, you owe only the 2.9% Medicare portion (plus any surtax) on your SE earnings, not the 12.4% Social Security portion.

Can I deduct half of my self-employment tax?

Yes. Under IRC §164(f) you deduct one-half of your SE tax as an adjustment to gross income on Form 1040, whether or not you itemize. This calculator shows that deductible half as one of its results.

What counts as net earnings from self-employment?

Generally your Schedule C net profit plus any guaranteed payments from a partnership, reduced by your deductible SE health insurance and retirement contributions where applicable. Gross receipts without subtracting business expenses overstate the base and overstate the tax.

When do I have to pay SE tax during the year?

SE tax is not withheld for you, so it flows into your quarterly estimated tax payments. Use Form 1040-ES to compute the installments due in April, June, September, and January; underpaying can trigger a penalty under IRC §6654.

Is SE tax the same as income tax?

No. SE tax funds Social Security and Medicare and is calculated separately from the income tax on the same profit. You pay both, though the one-half deduction and the deduction for half of SE tax soften the income-tax side slightly.

This calculator is an educational estimate only, not tax advice. The Social Security wage base and Medicare surtax thresholds change annually, and individual situations (partnership income, statutory employees, church employee income) alter the result. Confirm the current-year figures with the IRS Schedule SE instructions or a CPA.