We can only measure mass accurately - that's how we find most of them
Nope, we are talking mass.
DH Tau b is a planet, and is 37 times Jupiter's mass. See the link below
The entire list is at the link below and can be sorted by mass, which you'll note is measured in how many times of Jupiter's mass. Jupiter is the standard unit of measurement for exoplanets, since the vast majority that we have found are in Jupiter's range or greater. It's easier to detect them when they are that big, and they are definitely not brown dwarf stars, which start at 75 times Jupiter's mass.