How much is self-employment tax in Massachusetts?

The self-employment tax itself is federal: 15.3% on the first portion of net earnings (12.4% Social Security up to the wage base plus 2.9% Medicare). Massachusetts then adds its flat 5% state income tax on your business profit.

What is Massachusetts's income tax rate for the self-employed?

Massachusetts charges a flat 5% personal income tax on most income, including self-employment profit. A 4% surtax applies only to taxable income above 1 million dollars, so most freelancers pay the straight 5% rate.

Can I deduct half of my self-employment tax?

Yes. The IRS lets you deduct one-half of your self-employment tax as an above-the-line adjustment to income. This calculator applies that deduction before computing your Massachusetts state income tax.

Is the 92.35% factor really used?

Yes. Self-employment tax is calculated on 92.35% of your net earnings, which approximates the employer-side portion that an employee would not pay. Multiplying net profit by 0.9235 gives the amount subject to the 15.3% rate.

Does this include federal income tax?

No. This tool covers self-employment (Social Security and Medicare) tax plus Massachusetts state income tax only. Your federal income tax depends on your filing status, deductions, and bracket, and is calculated separately.

Massachusetts Self-Employment Tax Calculator

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Freelancers and independent contractors in Massachusetts owe two layers of tax on their business profit: the federal self-employment tax that funds Social Security and Medicare, and Massachusetts’s flat state income tax. This calculator combines both so you can set aside the right amount.

How it works

Self-employment tax is computed on 92.35% of your net earnings:

SE base = net earnings * 0.9235
Social Security = 12.4% of SE base, up to the annual wage base
Medicare = 2.9% of all SE base
SE tax = Social Security portion + Medicare portion

The first 12.4% (Social Security) applies only up to the annual wage base; above that, just the 2.9% Medicare rate continues. You may deduct one-half of the SE tax as an adjustment to income. Massachusetts then applies its flat 5% rate:

MA taxable = net earnings - (SE tax / 2)
MA state tax = MA taxable * 5%

A 4% Massachusetts surtax applies only to taxable income above 1 million dollars.

Example

On 80,000 dollars of net self-employment income, the SE base is about 73,880 dollars. The full amount is under the Social Security wage base, so SE tax is roughly 15.3% of 73,880, or about 11,304 dollars. Half of that, about 5,652 dollars, is deductible, leaving 74,348 dollars taxed by Massachusetts at 5% — or about 3,717 dollars in state income tax.

Notes

This estimate excludes federal income tax, the qualified business income deduction, and any local or industry-specific levies. The Social Security wage base and surtax threshold are updated annually. Always confirm current figures with the IRS and the Massachusetts Department of Revenue at mass.gov/dor, or work with a tax professional, before filing or making estimated payments.