Maryland Self-Employment Tax Calculator

The self-employment tax itself is a federal tax of 15.3% on 92.35% of your net profit — 12.4% for Social Security (up to the wage base) and 2.9% for Medicare. Maryland does not add a separate self-employment tax, but your net profit is still subject to Maryland state income tax (2% to 6.5%) and your county's local tax (2.25% to 3.3%), plus federal income tax.

If you expect to owe $500 or more in Maryland tax (or $1,000 or more federally) after withholding, you generally must make quarterly estimated payments. Self-employed people usually do, because no employer withholds for them. Missing these payments can trigger underpayment penalties from both the IRS and Maryland.

You can deduct one-half of your self-employment tax from your income before calculating federal and state income tax. It reflects the employer-share half of Social Security and Medicare that a normal employer would have paid. This calculator applies the deduction automatically before computing income tax.

Deduct every legitimate business expense to reduce net profit, since SE tax and income tax both apply to profit, not revenue. Contributing to a SEP-IRA or Solo 401(k) lowers income tax (though not the SE tax). At higher income, electing S-corporation status can reduce the SE tax base — worth discussing with a tax professional.

It is a planning estimate using 2026 rates. It does not model the qualified business income (QBI) deduction, retirement contributions, other household income, or credits, all of which can change your final number. Use it to size your quarterly payments, and confirm with a tax professional before filing.

To calculate it, first find your net profit (business income minus expenses). Multiply that profit by 92.35% to find your taxable base, then multiply by 15.3% to get your federal self-employment tax. You'll also owe federal income tax, Maryland state income tax, and local county tax on that profit.

There is no specific 'Maryland state self-employment tax'. The 15.3% self-employment tax (for Medicare and Social Security) is strictly federal. However, your self-employment net profit is subject to Maryland's regular state income tax brackets and local county taxes.

You can pay Maryland estimated taxes online using the Comptroller's website or mail a check with Form 502D. Federal estimated taxes can be paid online via the IRS Direct Pay system or by mail with Form 1040-ES. Payments are typically due in April, June, September, and January.