Connecticut charges 3-6.99% state income tax. Use the side income tax calculator pre-loaded with Connecticut rates.
Open Side Income Tax Calculator →Side income in Connecticut is subject to federal income tax at your marginal rate, self-employment tax if applicable, and up to 6.99% Connecticut state income tax. Because side income typically stacks on top of your W-2 salary, it is often taxed at your highest marginal rates. The combined marginal rate on side income can easily exceed 40% for mid-to-high earners. This calculator breaks down exactly what you keep from each dollar of side income in Connecticut.
Connecticut uses a graduated income tax with brackets ranging from 3-6.99%. Lower income is taxed at lower rates, with the 6.99% top rate applying only to income in the highest bracket. This progressive structure means your effective state tax rate is always lower than the top marginal rate. Connecticut does not have local income taxes, so the state graduated rate is the total state-level income tax burden.
The table below shows what you actually keep at five salary levels in Connecticut, accounting for federal tax, FICA, and Connecticut's graduated (3-6.99%) state tax.
See how Connecticut compares to other Northeast states. Each link takes you to the side income tax calculator landing page for that state.
For a comprehensive breakdown of Connecticut’s tax structure, salary comparisons, cost-of-living analysis, and more, visit the full Connecticut take-home pay page.