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How Self-Employment Tax Works in Connecticut (2026)
Self-employment tax is 15.3% — 12.4% Social Security plus 2.9% Medicare — applied to 92.35% of your net self-employment income, on top of federal and Connecticut income tax. Half of the SE tax (7.65% equivalent) is an above-the-line deduction against your federal taxable income.
| Piece | Rate / rule |
|---|---|
| Net earnings subject to SE tax | 92.35% of net profit |
| Social Security portion | 12.4% (up to $184,500 of net earnings) |
| Medicare portion | 2.9% · +0.9% above $200,000 |
| Deductible half of SE tax | 50%, above-the-line on your federal return |
Estimated payments are due quarterly (roughly mid-April, mid-June, mid-September, and mid-January). The 20% Qualified Business Income deduction (§199A) is not modeled here — it depends on your income level and business type. If you also have W-2 wages, the Social Security cap is measured against your combined earnings, so this estimate runs high.
Connecticut Self-Employment Tax by Income (2026)
Single filer, 1099 income is the only earnings for the year. The quarterly figure is an even 4-way split of the annual total.
| Net 1099 income | SE tax | Federal tax | Connecticut tax | Quarterly payment |
|---|---|---|---|---|
| $20,000 | $2,826 | $249 | $72 | $787 |
| $40,000 | $5,652 | $2,281 | $748 | $2,170 |
| $60,000 | $8,478 | $4,511 | $1,584 | $3,643 |
| $80,000 | $11,304 | $7,527 | $2,514 | $5,336 |
| $100,000 | $14,130 | $11,616 | $3,536 | $7,320 |
Connecticut Self-Employment Tax FAQ
How much is self-employment tax in Connecticut?
15.3% federal SE tax on 92.35% of net profit (12.4% Social Security up to $184,500, 2.9% Medicare), plus Connecticut income tax on net profit at 2.00%-6.99%, plus federal income tax. Half the SE tax is deductible federally.
Do I pay Connecticut estimated taxes as a freelancer?
Yes - Connecticut requires quarterly estimated payments once your unpaid state tax passes its threshold (check the Connecticut Department of Revenue Services), on the same mid-April / mid-June / mid-September / mid-January schedule as the IRS $1,000 federal rule.
Does Connecticut have a self-employment tax of its own?
No - the 15.3% SE tax is entirely federal. Connecticut just taxes your net self-employment profit as ordinary income at its regular bracket rates.
Methodology & Source
Connecticut state tax figures sourced from Connecticut Department of Revenue Services (https://portal.ct.gov/drs), citing Conn. Gen. Stat. § 12-700. Federal brackets, standard deductions (single/MFJ/HoH), and FICA constants sourced from the IRS (Revenue Procedure 2025-32; married-filing-jointly Additional Medicare threshold of $250,000 is a separate, unindexed statutory figure). Connecticut's married-filing-jointly and head-of-household figures are not yet independently verified and currently fall back to single-filer brackets — see the caveat in the formula section above.
Self-employment tax uses the statutory 15.3% rate (12.4% Social Security + 2.9% Medicare) on 92.35% of net self-employment income, with half of the SE tax deducted from federal taxable income above-the-line — per IRS Schedule SE (Form 1040) instructions, IRC §1401 and §164(f), 2026 edition. The 20% Qualified Business Income deduction (IRC §199A) is not modeled — it phases out by income and business type and is too state/entity-dependent to compute generically. This assumes the self-employment income is your only earnings for the year; if you also have W-2 wages, the Social Security wage-base cap and Additional Medicare threshold are actually based on your combined earnings, so this will overstate SE tax if you have significant wage income too.
This is an estimate based on standard single-filer federal, FICA, and CT state calculations. Actual withholding may differ based on your W-4 elections, pre-tax deductions, and other factors. Connecticut's $15,000 personal exemption phases out between $30,000 and $45,000 of income; this estimate applies it as a flat amount, which understates tax for filers in that phase-out band. Connecticut also has a "tax recapture" provision affecting high earners, not modeled.
Guideline version: 2026-CT-v1 · Effective: 2026-01-01 · Last verified: 2026-07-26