How long does the average 18 year old relationship last?
Christopher Snyder
Updated on March 05, 2026
How long the average relationship lasts for the age group of 16- to 18-years-old is close to the figure Fogarty cited for 15- and 16-year-olds. According to the National Institutes of Health, teenagers 16 years old to 18 years old have relationships that last 1.8 years.