Marlborough is a city located in Massachusetts. With a 2020 population of 39,815, it is the 37th largest city in Massachusetts and the 987th largest city in the United States. Marlborough is currently declining at a rate of -0.01% annually but its population has increased by 3.42% since the most recent census, which recorded a population of 38,499 in 2010. Marlborough reached it's highest population of 39,825 in 2018. Spanning over 22 miles, Marlborough has a population density of 1,909 people per square mile.
The average household income in Marlborough is $100,656 with a poverty rate of 6.29%. The median rental costs in recent years comes to $1,435 per month, and the median house value is $333,600. The median age in Marlborough is 40.2 years, 39.7 years for males, and 40.8 years for females. For every 100 females there are 89.6 males.