Not all of the couples in Friends were meant to be together, and some relationships ended just as quickly as they started. The characters had their fair share of romances that were fleeting and weren't important in the grand scheme of the show. However, there were some that were crucial, despite how long they lasted.
The Friends timeline isn't too hard to figure out, which gives fans an idea of how much time passed in the world of the show. Going off the assumption that all the couples who ended up together stayed together, the length of most of the relationships can be approximated by the information the show provides.
Rachel And Joey - A Few Days
Rachel and Joey weren't the most popular relationship when the series was on air, but as new viewers begin to watch the show on streaming services, they developed more of a following. It was obvious that Rachel was going to end up with Ross, so Friends didn't give Rachel and Joey much of a chance.
The writers made their romance seem forced and awkward, causing them to break up just a few days after they began to explore what was between them. Rachel and Joey may be the shortest relationship in Friends, but Joey's feelings for her were a pillar of the plot during the last couple of seasons.
Ross And Emily - About 2.5 Months
After Ross accidentally says Rachel's name when he's marrying Emily, their marriage ends before it even begins. While they continue on with the ceremony to appease the guests, Emily refuses to see Ross or go on their honeymoon.
Ross tells his friends, "I'm sending 72 long-stemmed, red roses to her parents' house. One for each day that I've known and loved her," clarifying that they dated for about two and a half months. Unfortunately, their relationship never recovers after Ross's mistake, and Emily files for a divorce.
Monica And Richard - About A Year
It's hard to know the exact amount of time Monica and Richard were together, but from examining the timeline, it's safe to assume that they dated for about a year. Their relationship came as a shock to Monica's parents, given how much older he was than her. Richard was also a family friend who knew Monica since she was a kid, making their dynamic a bit unprecedented, but still entirely consensual.
They ended up having a serious romance and were fully devoted to each other, but because of their age difference, their plans for the future didn't line up. Richard didn't want to have any more kids, while Monica couldn't imagine a life without them. Their breakup was civil and there were no hard feelings or love lost between them.
Chandler And Janice - On And Off For About 1.5 - 2 Years
Chandler and Janice's relationship was so all over the place it's nearly impossible to give it any sort of time frame. They were dating long before the pilot episode of Friends and broke up in early season 1. But their romance didn't end there, and the two of them were off and on for years.
Janice is one of the few exes who continued to pop up throughout the series, and Chandler kept going back to her until he fell in love with Monica. From what viewers know, Chandler and Janet probably dated a total of one-and-a-half to two years.
Ross And Rachel - About 1 Year +++
It's hard to believe given that Ross and Rachel were such a central couple, but the pair only dated for about one year onscreen. Ross had a crush on Rachel for his entire life and they finally got together in season 2.
They broke up during season 3 following the famous "we were on a break" incident, and although they had a baby after a secret hookup, they didn't get back together until the last few minutes of the series. However, if viewers are to assume that Ross and Rachel stayed together after the show ended, their relationship is much longer than those who were featured for more time onscreen.
Phoebe And Mike - About 1.5 Years +++
Phoebe and Mike may not have met until late in the series, but they dated longer than most of the other couples. They first started a relationship in season 9 and broke up after Mike admitted he didn't want to get married.
However, Mike realizes that he doesn't want to lose Phoebe, and they get back together when he shows up in Barbados. Phoebe and Mike get married in season 10, leading viewers to assume that they're together for life. Their onscreen romance probably lasted a bit longer than Ross and Rachel's, putting it at about a year and a half.
Monica And Chandler - 6 Years +++
Monica and Chandler were the most stable relationship of the friend group and they dated for about six years onscreen. During that time, viewers watched them reel from what was supposed to be a one-night stand in London to begin to accept that they couldn't write off whatever was between them.
Monica and Chandler got into plenty of fights, but they stayed together from season 5 onwards. The two proposing to each other was arguably the most emotional moment in the entirety of Friends, and they remained a grounding force in a hectic series.
Susan And Carol - About 10 Years +++
Carol had already left Ross for Susan in the first episode of Friends, and their relationship had been going on before the show started. Because of the timing of Carol's pregnancy, it's unlikely that she was with Susan for too long before the pilot, but that piece remains unknown.
Carol and Susan were together for the entirety of Friends and were one of the most loving and stable couples in the sitcom. They dated for about two years and were married for the rest of the series, putting their onscreen romance at about 10 years.