South Carolina Self-Employment Tax Calculator (2026)
Federal self-employment tax, federal income tax and South Carolina state income tax on 1099 income, plus the quarterly estimated payment to set aside.
- Total tax
- $16,320
- Effective rate
- 22.7%
- Per quarter
- $4,080
- After-tax income
- $55,680
| 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 Carolina income tax | $1,517 |
| Total federal + state | $16,320 |
Estimated payments of $4,080 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 Carolina income tax: calculated under the state's own rules, described below.
South Carolina and self-employment income
South Carolina rewrote its income tax for 2026: instead of starting from federal taxable income with brackets of 0%, 3% and 6%, the state now starts from federal AGI, allows its own $15,000 single / $22,500 head of household / $30,000 joint deduction (phasing out between $40,000 and $95,000 of income single, $80,000 and $190,000 joint) and taxes the result at 1.99% on the first $30,000 and 5.21% above. Two things stay: the exemption per dependent ($4,930 in 2025; the 2026 amount is not yet indexed), and the I-335 election that lets sole proprietors pay a flat 3% on active trade or business income — under the safe harbor, half of net profit after the half-SE deduction, for pass-through income up to $100,000 — which this calculator applies when it lowers the tax.
South Carolina rules used by this calculator (2026)
- South Carolina applies 2 brackets from 1.99% to 5.21% for 2026.
- Each dependent adds a $4,930 deduction.
- Standard deduction: $15,000 single ($30,000 joint), shrinking once income passes $40,000 ($80,000 joint) and gone at about $95,000 ($190,000 joint).
- South Carolina's earned income credit is 125% of the federal credit, nonrefundable, capped at $200; the calculator applies it.
- Sole proprietors may elect a flat 3% on active trade or business income; under the safe harbor that is 50% of net profit after the half-SE deduction for profits up to $100,000. The calculator applies the election when it lowers the tax.
- South Carolina starts from federal AGI, so the deductible half of self-employment tax reduces state income as well.
- South Carolina has no city or county income taxes.
What a South Carolina freelancer may still owe
- South Carolina requires estimated payments (SC1040ES) when you expect to owe $100 or more; the 2026 SC1040ES was printed before the reform and shows the old schedule — use the Department's Information Letter #26-20.
- There is no city or county income tax. Not included here: the extra exemption per child under six and the two-wage-earner credit.
- Applied here: South Carolina's earned income tax credit for full-year residents — 125% of the federal credit against the tax in 2025, capped at $200 from 2026 under Act 110.
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). South Carolina runs its own estimated-payment schedule with its own threshold (see above); the calculator's per-quarter figure combines federal and state so you can set aside one amount.
- 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
Does South Carolina tax self-employment income differently from wages?
For state income tax, net profit from self-employment is ordinary income like wages. The self-employment tax itself is federal only; South Carolina does not add a state equivalent.
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 Carolina 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 Carolina 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
- IRC §6654(d)(1)(B)–(C), (e)(1) and (f) (required annual payment: lesser of 90% of the current year's tax or 100% of the prior year's, 110% when prior-year AGI exceeds $150,000 / $75,000 MFS; no penalty when the tax less withholding is under $1,000; 'tax' = income tax + SE tax less credits other than withholding), read at law.cornell.edu; Form 1040-ES instructions, 'Who Must Pay Estimated Tax' and the Estimated Tax Worksheet
South Carolina figures for 2026: verified · last verified 2026-09-08
- Act 110 of 2026 (H.4216, signed 2026-03-30): S.C. Code §12-6-510(C) two-bracket schedule for tax years from 2026 (1.99% below $30,000; 5.21% less $966 at or above, all filing statuses, indexed), §12-6-1140(15) South Carolina individual adjustment deduction (SCIAD: $15,000 single and separate, $22,500 head of household, $30,000 joint and surviving spouse, phased out over $40,001–$94,999 / $60,001–$142,499 / $80,001–$189,999 of federal AGI, reductions rounded down to $10), and the new starting point at federal AGI with the federal standard, itemized, QBI, senior, tip and overtime deductions disallowed
- South Carolina Department of Revenue — Information Letter #26-20 (2026-08-31) and the Department's 'Information about H.4216' page: the 2026 brackets, the SCIAD amounts and phase-out windows, the federal-AGI starting point, the $200 EITC cap. (The 2026 SC1040ES, revised 2025-10-13, predates Act 110 and prints the old schedule.)
- S.C. Code §12-6-545 (I-335 election, untouched by Act 110) and §12-6-1140 (dependent exemption, untouched; the 2026 indexed amount is not yet published — the 2025 $4,930 is carried provisionally)
- South Carolina Department of Revenue — Revenue Ruling #08-2 (active trade or business income): the safe harbor's $100,000 test and the 50% share both use pass-through income after its deductions, including one-half of self-employment tax (Q10, Q16); $100,000 is the safe-harbor eligibility line, not a cap on the election
- South Carolina Department of Revenue — Form TC-60 (earned income tax credit: 125% of the federal credit for full-year residents, nonrefundable, entered on SC1040TC code 060 → SC1040 line 13; agency example $1,190 × 125% = $1,488); S.C. Code §12-6-3632
- Act 110 of 2026 (H.4216) §7: the credit is capped at $200 for tax years beginning after 2025