If you look at the sides of your carseat it will tell you we have the joie sprint and it's 50-75cm
Ours said on the back of the newborn insert and was by length. Ours said over 60cm so check the back of the insert.
Ours is the same as @Melissa’s and we removed it a few days ago. He’s 13 weeks now. He defo looked a bit too snug in it before we removed it!
Our car seat goes by height and on ours it was when they got to 60cm’s x