Median household income is a gauge of the overall economic health of the region and the financial resources of households.

In 2017-21, the median household income in Brookline was $122,400, 13% higher than the median income in 2000 of $108,503 (after adjusting for inflation). In 2017-21, the state had a lower median household income at $89,000 and the nation was substantially lower, at $69,000. Brookline's 13% increase since 2000 compares with an 8% increase at the state level and a 1% increase at the national level.

Compared to Brookline, the median income in Newton was much higher at $164,600 and slightly higher in Arlington at $125,700. Median incomes in both Cambridge and Everett were lower than Brookline at $112,600 and $71,500 respectively.

Figures are in constant 2021 dollars. The multiyear figures are from the Census Bureau's American Community Survey. The bureau combined 5 years of responses to the survey to provide estimates for smaller geographic areas and increase the precision of its estimates. However, because the information came from a survey, the samples responding to the survey were not always large enough to produce reliable results, especially in small geographic areas. CGR has noted on data tables the estimates with relatively large margins of error. Estimates with 3 asterisks have the largest margins, plus or minus 50% or more of the estimate. Two asterisks mean plus or minus 35%-50%, and one asterisk means plus or minus 20%-35%. For all estimates, the confidence level is 90%, meaning there is 90% probability the true value (if the whole population were surveyed) would be within the margin of error (or confidence interval). The survey provides data on characteristics of the population that used to be collected only during the decennial census. Data for this indicator are released annually in December.