South Dakota Self-Employment Tax Calculator (2026)
Federal self-employment tax, federal income tax and your quarterly estimated payment on 1099 income earned in South Dakota. South Dakota has no state income tax, so the total below is what you owe.
- Total tax
- $14,803
- Effective rate
- 20.6%
- Per quarter
- $3,701
- After-tax income
- $57,197
| Breakdown | |
|---|---|
| Net profit (income − expenses) | $72,000 |
| Self-employment tax | $10,173 |
| Social Security (12.4%) | $8,245 |
| Medicare (2.9%) | $1,928 |
| Federal income tax | $4,630 |
| Adjusted gross income | $66,913 |
| Standard deduction | −$16,100 |
| Qualified business income deduction (20%) | −$10,163 |
| Taxable income · marginal rate 12.0% | $40,651 |
| South Dakota income tax | None |
| Total federal + state | $14,803 |
Estimated payments of $3,701 are due Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027.
How the 2026 numbers are calculated
- Net profit is your 1099 income minus deductible business expenses (Schedule C).
- Self-employment tax is 15.3% of 92.35% of net profit: 12.4% Social Security on the first $184,500 of combined wages and net earnings, plus 2.9% Medicare on all of it. An extra 0.9% Medicare tax applies above $200,000 ($250,000 married filing jointly).
- Adjusted gross income is net profit plus any W-2 wages, minus half of the self-employment tax.
- The standard deduction ($16,100 single, $32,200 married filing jointly, $24,150 head of household) and the 20% qualified business income deduction reduce taxable income. The QBI deduction starts phasing out above $201,750 of taxable income ($403,500 joint).
- Federal income tax is applied to what is left using the 2026 brackets for your filing status.
- The child tax credit ($2,200 per child under 17, $500 per other dependent) reduces income tax; up to $1,700 per child is refundable and can offset self-employment tax.
- The earned income credit for filers with children — up to $4,427 with one child, $7,316 with two, $8,231 with three or more — is fully refundable and phases out above $23,890 of income ($31,160 joint).
- South Dakota income tax: none. See below for what the state does collect.
South Dakota and self-employment income
South Dakota has no personal or corporate income tax. Freelancers pay federal self-employment and income tax only.
What a South Dakota freelancer may still owe
- South Dakota taxes most services under its sales tax, so a freelancer selling services to in-state clients may need a sales tax license.
Quarterly estimated tax deadlines (2026)
If you expect to owe $1,000 or more of federal tax for the year, the IRS expects four estimated payments (Form 1040-ES). Because South Dakota has no income tax, there is no separate state estimate to make.
- Federal payment 1: April 15, 2026
- Federal payment 2: June 15, 2026
- Federal payment 3: September 15, 2026
- Federal payment 4: January 15, 2027
The calculator splits your total into four equal payments. To avoid an underpayment penalty you can instead pay 100% of last year's total tax (110% if your prior-year AGI was over $150,000) spread across the four dates.
Common questions
Do I pay self-employment tax if South Dakota has no income tax?
Yes. Self-employment tax is a federal tax that funds Social Security and Medicare. It applies in every state regardless of state income tax.
Is half of self-employment tax really deductible?
Yes, for federal tax. The employer-equivalent half is an adjustment to income on Schedule 1, which lowers your AGI and therefore your federal income tax. It does not reduce the self-employment tax itself.
Does an LLC change these numbers?
A single-member LLC taxed as a sole proprietorship pays exactly what this calculator shows. Electing S-corporation status changes the math (salary plus distributions) and is outside this tool's scope.
What if I moved to South Dakota during the year?
Income earned while you were a resident of another state is taxable there under that state's rules. This calculator assumes all income was earned as a South Dakota resident.
Data sources and status
Federal figures for 2026: verified · last verified 2026-09-05
- IRS Rev. Proc. 2025-32 (2026 inflation adjustments, incorporating OBBBA changes)
- SSA 2026 COLA fact sheet — Social Security wage base
- 26 U.S.C. §199A as amended by Public Law 119-21 — QBI phase-in range widened to $75,000 / $150,000
- 26 U.S.C. §24 as amended by Public Law 119-21 — CTC $2,200, indexed from 2026
- IRS Form 1040-ES (2026) — estimated tax due dates
- IRS Rev. Proc. 2025-32 §4.06 — earned income credit amounts and §32(i) investment income limit