Sadly, you'll need a different tape measure for that depending on where you live. It is generally 4.5 feet in the US, 1.3 meters in Europe, and 4'7" in Australia. In most cases, it is close enough to just your your own (adult) breast. I prefer to take a supermodel with me for use as a measuring device.And what is the international standard for breast measurement ?
DBH is used for estimating the volume of wood in a tree or stand of trees.
https://en.wikipedia.org/wiki/Diameter_at_breast_height