2025 Tax Year

Connecticut Side Hustle Tax Calculator

Calculate your Connecticut state tax (5.50%), federal tax, and self-employment tax on 1099 income.

CT5.50%

3.6 million residents

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2025 rates

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Last updated: January 2026 · Data from IRS Rev Proc 2024-40

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State

W-2 Income (from your day job)

Side Hustle Income *

Business Expenses (optional)

Connecticut side hustlers face a progressive state income tax system with rates that can reach 6.99% at the highest levels. However, for most freelancers earning typical side hustle income, the effective rate is around 5.5%. The Constitution State has a strong economy centered around Hartford, New Haven, and Fairfield County, with many residents commuting to New York City for work while running side businesses.

Connecticut Tax Guide

How Side Hustle Taxes Work in Connecticut

Connecticut uses a progressive income tax system with seven brackets:

**Connecticut state tax rates (2025):** - 3% on income up to $10,000 (single) - 5% on $10,001 - $50,000 - 5.5% on $50,001 - $100,000 - 6% on $100,001 - $200,000 - 6.5% on $200,001 - $250,000 - 6.9% on $250,001 - $500,000 - 6.99% on income over $500,000

**No local income taxes:** - Hartford, New Haven, Stamford, and all Connecticut cities do not levy income taxes - You only pay the state progressive rate plus federal taxes

Example

What Connecticut Side Hustlers Owe

Let's say you're a single filer in Hartford with a $55,000 W-2 job and $17,000 in side hustle income from freelance consulting, with $2,500 in business expenses.

**Your estimated taxes on the side hustle:** - Net self-employment income: $14,500 - Federal SE tax (15.3% of 92.35%): ~$2,051 - Federal income tax on side income: ~$3,190 (22% bracket) - Connecticut state tax (5.5%): ~$798 - **Total additional tax: ~$6,039**

Your effective rate on the side hustle is approximately 42%.

Important Dates

Connecticut Tax Deadlines 2025

Connecticut estimated tax deadlines: - **Q1**: April 15, 2025 - **Q2**: June 16, 2025 - **Q3**: September 15, 2025 - **Q4**: January 15, 2026

Use Connecticut Form CT-1040ES for state estimated tax payments.

Save Money

Common Deductions for Connecticut Freelancers

Connecticut freelancers should maximize deductions to reduce their progressive state tax burden. **Home office expenses**: Claim dedicated business space using simplified ($5/sq ft) or actual expense method—valuable given Connecticut's high housing costs. **Business mileage**: 67 cents/mile for 2025; important for those traveling to client sites in Hartford, New Haven, Stamford, or into NYC. **Equipment and software**: Computers, cameras, tools, and business software are deductible. **Professional services**: Accounting, legal, and tax preparation fees are fully deductible. **Health insurance premiums**: Self-employed individuals can deduct 100% of health insurance costs. **Retirement contributions**: SEP-IRAs and Solo 401(k)s reduce federal AGI, which Connecticut uses as its starting point—saving you at federal rate plus up to 6.99%. **Marketing expenses**: Website costs, business cards, and promotional materials are deductible. Connecticut uses federal AGI as its starting point, so all Schedule C deductions automatically reduce your CT taxes. Every dollar deducted saves you 5-6.99% in state taxes depending on your bracket.

Common Questions

Connecticut Side Hustle Tax FAQ

What is Connecticut's tax rate on side hustle income?

Connecticut has progressive rates from 3% to 6.99%. Most side hustlers with income between $50,001 and $100,000 pay 5.5% on their marginal earnings.

Does Connecticut have local income taxes?

No, Connecticut cities and towns do not levy local income taxes. You only pay state-level income tax on your side hustle earnings.

How does Connecticut compare to New York?

Connecticut's rates are generally lower than New York State, and CT has no equivalent to New York City's additional income tax. This makes CT attractive for NYC commuters.

Do I need to register my side hustle in Connecticut?

Sole proprietors using their legal name don't need state registration. If using a trade name (DBA), file with your town clerk. LLCs must register with the Connecticut Secretary of State. Sellers may need a Sales Tax Permit from the Department of Revenue Services.

When are Connecticut quarterly estimated taxes due?

Connecticut follows federal quarterly deadlines: April 15, June 16, September 15, and January 15. Use Form CT-1040ES for payments.

Is living in Connecticut better than NYC for tax purposes?

For side hustlers, potentially yes. Connecticut has no local income tax, while NYC residents pay an additional 3-3.9% city tax. A freelancer earning $50,000 in side hustle income could save $1,500-$2,000 annually living in CT vs NYC.

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