How to measure the width of a string?

I'm using text mesh pro but need to format in ways that are not supported, like keeping the first and last name on the same line and using a custom overflow indicator. I wrote a script that did this by keeping track of how many characters are on the line to see if the word or pair of names will fit but it is not accurate enough. I'm looking for a way to measure the width of the word so that it takes into account the variation in character widths and the difference between lower/upper case.