How Connecticut withholds on a bonus
Connecticut is one of the states with no flat supplemental rate. Its employer guide directs that a bonus be added to the regular wages for the period and withheld on the combined amount under the tables for the employee's withholding code (A through F on Form CT-W4), which is the aggregate method whether or not the employer uses it federally. The calculator therefore applies Connecticut's graduated brackets to the combined paycheck and subtracts the regular withholding, whichever federal method is shown.
For a $60,000 single filer paid every two weeks, that puts most of a $10,000 bonus in Connecticut's 5.5% bracket, about $550 of state withholding, alongside $2,200 federal, $620 Social Security and $145 Medicare under the percentage method, leaving roughly $6,485. Connecticut Paid Leave's 0.5% is also withheld from a bonus up to the Social Security wage base, about $50, and is not included here. There are no local income taxes.
What the withholding means for your Connecticut return
Because Connecticut withholds under its actual brackets rather than a flat rate, the state line on a bonus is usually close to the tax owed, and closer than in flat-rate states where the supplemental rate is set at the top bracket. The federal 22% is where the refund comes from for most filers: a $60,000 single filer's marginal federal rate is 12% to 22%. Connecticut's tax benefit recapture and personal credits, which the calculator does not model, can move the state figure by a few dollars either way. The Connecticut paycheck calculator shows the marginal rates for any salary.