Cos Cob, CT population, income and ZIP codes

Cos Cob CDP is a mid-size town in Connecticut, with 7,354 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #47 of 215 ranked by population — larger than 78% of them. The median age here is 39.3 years against 39.1 nationally, a slightly older profile than the country as a whole. Places under 65,000 residents only appear in the five-year release, never the one-year file, so these values pool sixty months of responses and lag the current year by design.

Households in Cos Cob CDP earn a median of $176,602 a year, 124.9% above the national figure of $78,538 and 83% above the $96,484 median for the 159 Connecticut cities we cover. The median is the midpoint household, not an average, so a handful of very high earners cannot drag it upward the way they distort a mean. Poverty reaches 5.5% of residents here, less than half the 12.4% national rate.

The typical owner-occupied home in Cos Cob CDP is valued at $1,149,500, 278.9% above the national figure and 234% above the $344,200 peer median, while median gross rent runs $2,574 a month, 83.1% above the national figure, or roughly $30,888 across a full year. A household on the local median income would put about 17.5% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is cheap relative to what people here earn. The home-price-to-income ratio works out to 6.5×, against roughly 3.9× nationally, so buying is out of reach on local earnings alone and the ownership market leans on outside income, equity or dual high earners. 65.4% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. Rent is reported gross — contract rent plus tenant-paid utilities — which is why it runs above the advertised price on a listing for the same unit.

Home values sit at 6.5× median household income, far past the 3.9× national mark, so ownership costs here are set by something other than local wages — second homes, retirees with equity, or commuters earning elsewhere.

No figure on this page is estimated by us; each one comes straight from the published ACS tables for this area. Small-area estimates still carry wider margins of error than state or national figures, so check the linked ACS tables before relying on them for lending, appraisal or legal work.