What is a sure-fire way of knowing whether or not a horse is a weight carrier?

[Cowgirl@heart]

I've heard many different opinions regarding my question.

Take the weight of the horse and divide it by rider and tack weight...

Measure the cannon bone circumference......

Is there a fool-proof and sure-fire way of knowing whether or not a horse can carry weight (90+ kg) without having to measure/weigh anything???

I've also heard that one can judge by looking at the width of the horse's cannon bone (big/wide cannon bone = weight carrier). It also depends on the type of riding and distance. Also on whether you'd be walking, trotting, cantering. Whether the paths are ok (not too hard/not too soft/not too bumpy/not too many hills, etc.)

I don't know, any advice would be greatly appreciated!!! 

[Presence]

Cowgirl I've never heard of "measuring" a horse to see if it is able to carry weight.  IMO if the horse looks comfortable he/she is able to carry the weight. But some horses have bad backs, so after a while it can become a problem.

Personally I think it all depends on the rider.  I know a woman who weights 90kg and she rides a slim 15hh horse. She is a good rider with good balance and a light seat. The horse has no problems with the weight.

Best thing would be is to buy a big horse, lol!