Another factor to consider is that your toes/feet should be able to fit under the table so that you can stand close enough to it. Another idea is to rest a foot on a stool ( switching them periodically) if you are going to be standing for long periods of time, it will help take the strain off of your back.
Play with your ironing board, and find a height that feels comfortable to cut from, then measure that height and go from there :wink: