[AnnaLouise2012]

Mum: Arab x hannoverian 15.3
Dad: polish warmblood 16hh
I know the mum's dad was big too but I don't know the height.
How big will the foal likely reach?
Thanks

[sabrina]

Can vary. I had 3 foals out of the same mare who was 15 hands, same sire 15.2 hh. First foal, filly adult height 15 hands, 2nd foal filly 15.2 hh 3 foal colt who was gelded 16.2 hh. It all depends what heights are in the genes, how they are fed and looked after.

[smiley bucket]

Take an average of both, but could go either way.
Found this fiddly way online..... you'll need a horse measuring stick  and you will need a piece of string about three and a half feet long.
 
Have a handler hold the horse still while you take one end of the string and place it at her front leg elbow. Next, stretch the string down to the ground, and mark it or tie a knot in it at the horse's fetlock-level.
Next, take the string, put one end on the horse's elbow again in the same spot as before, and now stretch the string up so that it is up in the air over her back. The knot in the string, or the place where you marked it, is approximately at the height where her withers will be when she is full-grown. Keep the knot or mark at that height and now use the measuring stick to tell you how tall she will be. This is usually fairly accurate within an inch or so.
What do you hope to do with the foal?  Did you breed it or buy it?