North Dakota Self-Employment Tax Calculator

A North Dakota freelancer earning $80,000 pays about $11,300 in federal self-employment tax — and roughly $293 to the state. That 40-to-1 ratio is the defining fact of self-employment taxation in North Dakota: the state runs one of the lowest income taxes in the country (a 0% bottom bracket and a top rate of 2.5%), so nearly all your planning attention belongs on the federal 15.3%. This calculator computes both layers in the correct order, including the deductible half of SE tax that shrinks the state base.

The calculation order

The calculation runs federal SE tax first, then North Dakota income tax on the reduced base:

SE base       = net profit x 0.9235
SE tax        = SE base x 15.3%  (12.4% SS up to wage base + 2.9% Medicare)
half SE tax   = SE tax / 2  (deductible)
state base    = net profit - half SE tax - standard deduction
ND income tax = ND brackets applied to state base
total tax     = SE tax + ND income tax

The 92.35% factor removes the employer-equivalent share, and the half-SE-tax deduction lowers the income on which North Dakota’s brackets apply.

The North Dakota brackets the tool models (2024 structure):

North Dakota compressed its old five-bracket system into this three-bracket structure in 2023, zeroing out tax for a large share of filers — a single filer’s first ~$59,000 of profit (standard deduction plus the 0% bracket) generates no state tax at all. The federal SE tax figures use the 2024 Social Security wage base of $168,600; the SSA has since raised it ($184,500 for 2026), so high earners should treat the Social Security line as slightly conservative for later years.

Worked example

A single freelancer with $80,000 net profit:

• SE base: 80,000 x 0.9235 = $73,880
• SE tax: 73,880 x 15.3% = $11,303.64
• Half SE tax deduction: $5,651.82
• State base: 80,000 - 5,651.82 - 14,600 approximately $59,748
• North Dakota income tax approximately $293 (very low rates).

Why the North Dakota state tax is so small

The worked example above shows a freelancer with $80,000 in profit paying roughly $11,304 in federal SE tax but only about $293 in North Dakota state income tax. That ratio is not unusual. North Dakota’s 0 percent bottom bracket, very low top rate of 2.5 percent, and the use of the federal standard deduction (which is already subtracted at the federal level before North Dakota starts its calculation) combine to produce a state tax that is a small fraction of the federal SE tax. For self-employed North Dakotans, the federal SE tax is the dominant tax burden — often thirty to forty times larger than the state income tax on the same income.

Managing quarterly estimated payments

Self-employed people in North Dakota must make quarterly estimated tax payments to both the IRS and the North Dakota Office of State Tax Commissioner to avoid underpayment penalties. A safe-harbor approach is to pay 100 percent of the prior year’s tax in equal quarterly installments (or 110 percent if your prior year federal AGI exceeded $150,000). Given North Dakota’s low state rates, the state quarterly payment will be modest, but the federal SE tax quarterly payment can be substantial — use this calculator to estimate both so you know how much to set aside each quarter.

What counts as deductible business expenses

SE tax is computed on net profit, not gross revenue. Business expenses that reduce net profit directly reduce SE tax. For North Dakota freelancers, common deductible expenses include home-office costs (if exclusively used for business), business equipment and software, professional subscriptions, health insurance premiums (deductible as an above-the-line adjustment separately from SE tax), and any other ordinary and necessary business expenses. The lower your net profit, the lower your SE tax and your North Dakota income tax.

Tips

• SE tax dwarfs state tax. In North Dakota the federal SE tax is by far the larger number — plan cash flow around the 15.3 percent.
• Pay quarterly. Split your combined annual tax into four estimated payments to avoid underpayment penalties from both the IRS and North Dakota.
• Wage base caps Social Security. The 12.4 percent Social Security portion stops once earnings pass the annual wage base; Medicare’s 2.9 percent has no cap, and high earners also owe an additional 0.9 percent Additional Medicare Tax above a threshold.

Sources

• IRS — Self-employment tax (Social Security and Medicare taxes)
• Social Security Administration — Contribution and benefit base
• North Dakota Office of State Tax Commissioner

Estimate only, not tax advice. Models the 2024 SE parameters and North Dakota’s three-bracket structure; the 0.9% Additional Medicare Tax, credits, and ND-specific adjustments are not modeled. Confirm with Schedule SE and the state’s current-year forms. All math runs locally in your browser.