20 month colt, will he grow?

What is his breed? QH? If he's a stock-type breed he may remain rump-high, some horses in the stock-type breeds don't get very tall and remain pretty compact.

By about 18 months most horses have completed 85% of their growing in height. It is possible to see a couple of inches or so between now and when he is five-six years old, but another six or seven inches is kind of unlikely. Keep in mind though that a hand is only 4in, so an added decimal point is only one additional inch. He may yet reach 14hh in the next few years, but unfortunately, don't be surprised if he doesn't.

ETA: Based on his breeding, chances he reaches 14.2hh is iffy. I would keep an eye out more for the 13.3hh or 14hh range.

Up to 18 months horses have generally completed the growing in their legs, so height is gained through the mid-section up. The last bones to finish growing are in the back and these generally don't contribute to height (except for the withers). Imagine a horse is an elevator, they grow in an ascending fashion with age.

It really depends on the horse and how well he was fed when younger. Horses that are fed well with quality grain when younger, tend to grow faster and finish growing sooner, while horses that were not fed well as while they were in the growing stage tend to grow slower BUT for a longer period of time, so that the final difference in height is not all the great (there is one but if the feeding regime is increase before the horse is finished growing then the difference in height potential is not as major as most people think--usually being an inch or less).

There is also a lot of variation. I have had horses that were finished growing in height at 3 and I honestly had one gelding that I owned and measured as a 5 year old, who when measured again as a 7 year old had grown 3/4 of an inch.

He should continue to grow until he's five or six years old. But the rate he will grow, how fast and how much, will depend on how good he's cared for and what breed of horse he is. If he's a breed that only grows to be an average of 15 hands, then you shouldn't expect him to grow any taller than that. I had a filly once (AQHA Quarter Horse), who did the majority of her growing between 4-6 years old, she ended up finishing out at 16.3". It all depends on the individual horse really, good luck with your colt!

My QH continued to grow until he was almost 6 years old. The last 6 months was more filling out. I was fearful that he was not going to have that beautiful QH jaw line, but he just kept changing and filled out well and has a beautiful face. Just give him some time. He has quite a gene pool, but he should grow more, especially if he looks downhill from his croup. He is still very young but he will probably come around nicely for you given time.

That`s wrong

He will not stop growing untill about 5 year`s old though it might be a year early or year late depending on his breed as some breed`s grow quicker.

I think he should be close to his 14.2hh mark.

If horses finished growing as yearlings, then every horse on earth would be tiny. Whoever told you that is an IDIOT.

Yes your horse will continue growing.

He can grow more. Give him til 5 yo

should make the 14.2 mark.