How much does a horse that is 15 hands tall
weigh

Offering around 90% accuracy, weigh tapes are a convenient way of gauging your horse’s weight. Most tapes are double sided, one side calibrated to provide figures for ponies under 14.2hh, the other for horses above 14.2hh. To use a weight tape:

Stand your horse on a firm, level surface and encourage him to stand square; he should be relaxed with his head in his ‘normal standing’ position.
 Drop the tape over the lowest part of his whithers, making sure that you have the relevant horse / pony side facing you for easy reading. 
 Draw the tape around your horse so it sits close to his front legs, following a slight angle from the top of the tape on the whither (if the tape drops vertically down, it is too far back). Ensure the tape is firmly around the horse - but not so tight that it causes an indent into the flesh - as this will make the reading inaccurate. 
 Some tapes will allow you to read a figure off directly that represents the estimated weight of the horse,  whereas others may require you to take additional measurements and use in a formula – in this case, follow the manufacturer’s instructions.

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