What's your favorite way to determine how tall your foal will get?

[LostandFound]

I've seen people measuring cannon bones, going off how tall they were born, doing a string test, going by when the tail reaches the ground, and other ways. What do you use, and what do you think is the most accurate? Larry is an absolute monster, I think he is going to be big enough to ride. But when I did the cannon bone measure thing with the chart I get him maturing at 34". In the past I have always figured somewhere between the parent's heights is the best bet, but I notice almost no mini people do that, so I'm curious what way you all like best. And here is a picture of the cute little monster.

 

[chandab]

Between parents heights doesn't always work with minis, as you have to check their background for heights as well (grands, greats, etc). I have one that is 36" tall, both parents were under 34" (sire was 29-30" tall). By the same token, one mare is exactly half way between parents at 33.5"; sire 31", dam 36".
Cannon bone measurement might be closest, I've never been that worried about it, so haven't kept track of height.

 

[LostandFound]

I hadn't even thought of getting bigger than the parents. Usually what I see is horses listed for sale as going to be 33".... even though it's 32" at 6 months old and both parents are 38". I wasn't too worried, but I'm going to be selling him and the first thing everyone wants to know is how big he will get.

 

[Standards Equine]

I only just tried the string measurement of the front cannon this year with my yearling horse. It says he's going to mature 16.3 - 17 hh! That's taller than his mom, who is just shy of 16.3, and his daddy, who is 14.2 on the money (yes, we bred them on a hill and he stood on his tippy toes!) I laugh at the old wives tale of how the first-born foal is always small. This colt and his mom are both first-born foals and both are taller (or will be) than their dams.
Regarding littles, my favorite method is waiting until they're 5 years old and then measuring them.

 

[DB Minis]

I'm a bit obsessed about figuring out my yearlings' adult heights, mostly for fun but also because I hope for them to provide future lead line rides for little ones, so fingers are crossed for taller! From what I've read, the string test was thought to be the most accurate, but now I'm seeing two different types of string test. I had read about the string test measuring from the front of the cornet band up to the center of the knee, the resulting inches being the adult hand height. Now I also see another type of string test, measuring from the ergot to the point of elbow then bringing the bottom of the string up above the withers for the adult height (essentially doubling that string length for height measurement). It would be interesting to try both on the same horse to see how they line up.

Never heard of the idea of when the tail reaches the ground, I'm sure that's quite inaccurate due to good or bad hair genetics, but I love the sound of it! My large mini's tail is pretty much at the ground but my pony still has a ways to go - woohoo!

 

[LostandFound]

I've always heard of the string test being done from elbow to ergot. Now I need a piece of string to check the adults. When I went to get my stallion measured I was nervous, and someone did the measurement of the cannon for me. Told me he would be 34" and he made it. Everyone is in today because it was raining this morning. I'm sure they won't mind me doing bizzare measurements on them.

 

[LostandFound]

ok, the string test was wildly inaccurate on my 2 grown minis. They were both quite a bit shorter than it showed. I measured from elbow to ergot, then swung it up from the elbow.
Then I measured from the middle of the knee to the top of the hoof on all of them. The stallion was 8", he measured in at 34". Mare was 8.5", a barn measurement without setting her up gets her at 35.5" If she were set up she would probably do 35". And the colt comes in at about 8.25" So if that's accurate ish he should probably mature a smidge smaller than the mare, which means he is almost full grown at 6 months.