Thanks OP for starting this - I still get confused by the UK 'hh' and cm!! And THANKS star* for that!!!

I'm going to attempt to copy and print it out! It's the most useful thing I could keep with me when horse buying!!
The problem I have over here is HOW the horses are measured. Often adverts say for example, (translated obviously) '158 by the tape' or '175 by the stick' depending on whether the horse has been measured by a measuring stick or a height tape....! Here, the tape isn't held tight upright and read at 'eye level' across the withers, it's measured from the ground, following the horse's shape, held flat against the skin, to the wither. It can cause so much confusion, as 'in my way of thinking' a horse advertised at a certain height can in fact be 'slightly smaller'....!!!
I travelled miles into the middle of hellish nowhere to a rotten run-down farm to a '158cm' mare for sale - no one knew it it was 'by the stick' or 'by the tape' when I phoned up ..... so I took my measuring stick with me....
I looked over a couple of doors at some ponies, the asked to see the horse.... I was proudly shown a little scrappy pony who just about scraped 13hh (132-ish cm!) on my stick! I'd 'guestimated' that even '158 by the tape' would be at least 14.2!!!
I asked how they had measured her to make her '158cm'... The seller then showed me how he wrapped the tape around every slight contour of the pony's legs, elbow, and shoulder, up to the wither (well, halfway up the neck!) and over a little!!
No 158cm jmb height certificate for that mare!!
No-one understands 'hh' out here - just the 'stick' and 'tape' thing!
And I'm hopeless at maths, so I don't even begin to try and 'convert'!!
