By age 16, relationships last an average of two years, writes Fogarty. Most long-term relationships do not occur early, and during the teen years, you are likely to see group dating, according to Melanie Greenberg, Ph. D., in the article titled The Neuroscience of Relationship Breakups, in Psychology Today.

How long do most HS relationships last?

So, How Long Does The Average High School Relationship Last? Teenagers between the age of 16 to 18 years have a high school relationship for about 1.5 to 1.8 years. Some high school relationships only last till they move to college.