Sheldon & Missy's Age in Young Sheldon Season 6 Explained: How Old Are They?

Season 6 of Young Sheldon is nearing its end, which means that we will soon witness a storm of rapidly unfolding events that will affect the fate of the entire Cooper household.

While we do know about these upcoming developments from the stories Sheldon shared in The Big Bang Theory, one important aspect remains somewhat confusing for both old-time and new fans of the franchise — how old are Sheldon and his twin sister Missy exactly?

One of the plot points for navigating the chronology is the death of the Cooper patriarch, George Sr. From TBBT, we know that he died from a heart attack shortly before 14-year-old Sheldon left for a summer program in Germany. But at the end of Young Sheldon Season 6, George Sr. is alive and seemingly well, which makes you want to clarify the dates and see how old his children are now.

In the episode 'A New Weather Girl and a Stay-at-Home Coddler,' which aired on May 4, Sheldon is worried about his own resume as he sees his classmates already trying to gain experience by going to various summer programs. Being a child prodigy isn't enough for him to get into his dream university, Caltech, so Dr. Sturgis suggests he apply to an international program in Germany.

According to TBBT, Sheldon was 14–15 years old when he went to Germany, and we can assume that the Young Sheldon character will go abroad either this year or next year. This leads us to conclude that he and his twin sister Missy are now 13–14 years old.

There is another piece of evidence suggesting that the characters are 13. In Season 6, the Young Sheldon protagonist has not yet experienced the traumatic moment of catching his father cheating on his mother Mary, which we learned about from Season 10 of the original series. It's likely that the prequel will feature the dramatic storyline in the subsequent seventh season (that is, if the writers decide to cover it at all).

Also, in Episode 18 of the current sixth season, Sheldon's elder brother Georgie turned 18. We know that he was born in March 1975, and the twins were born in February 1980. Since Sheldon and Missy are five years younger than Georgie, they must be 13 and turning 14 next season.

Of course, it may turn out that the writers haven't thought deeply about the chronology, and they may choose to shake up the order of events to take place in the future episodes of Young Sheldon. In particular, Sheldon may go to Germany before his father dies and he turns 14.

We'll see what the future holds for the Young Sheldon characters in the follow-up episode, scheduled to air on May 11, as well as the two-part finale, which will arrive on CBS on May 18.