South Plainfield, NJ population, income and ZIP codes

South Plainfield borough is a mid-size town in New Jersey, with 24,231 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #43 of 700 ranked by population — larger than 93% of them. The median age here is 41.7 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 South Plainfield borough earn a median of $126,063 a year, 60.5% above the national figure of $78,538 and 18% above the $106,926 median for the 543 New Jersey cities we cover. Median household income counts every pre-tax dollar arriving at an address — wages, self-employment, Social Security, pensions, interest and public assistance — for everyone living there, so multi-earner households pull the figure up even where individual pay is modest. Poverty reaches 3.6% of residents here, less than half the 12.4% national rate.

The typical owner-occupied home in South Plainfield borough is valued at $443,900, 46.3% above the national figure and 8% above the $412,500 peer median, while median gross rent runs $1,928 a month, 37.1% above the national figure, or roughly $23,136 across a full year. A household on the local median income would put about 18.4% 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 3.5×, against roughly 3.9× nationally, so buying is easier here than in the average US market. 85.2% of occupied homes are owner-occupied versus 65% nationally, an owner-dominated market where rental listings are scarce and rent medians rest on a thin sample. Gross rent folds in the utilities a tenant pays separately, so it is closer to the real monthly outlay than a headline rent figure.

All values below were released by the Census for this exact geography, with no gap-filling on our side. 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.