How long did they stay in clothing sizes?

I thought J, who is 20 months, would be in 18-24m by now but he's been in 12-18 since July and definitely is not growing into 18-24 anytime soon. He probably won't be in it until next summer, and the fall/winter I bought him for this year in the bigger sizes will probably fit next fall! ha.

His growing has slowed significantly.

Once your child was 18+ (or maybe 2year+) how long did they stay in specific sizes?

I guess I always assumed that once they hit 2T they'd stay in it for a year then move up - but mine just might take longer than that.