HOW DO YOU MEASURE PUTTER LENGTH FITTING FOR A LEFT HAND LOW PUTTING STROKE.
A good, simple way is to assume your usual putting stance without a putter, then, without changing position, have someone place a putter in your hands. In this way, you’re not adjusting to whatever the putter’s length might be.
And here’s a link to a previous question on putter fitting – http://ralphmaltby.com/forum/question/putter-fitting-guide-how-to-determine-what-length-is-correct/?show_answer=3402#answer_3402
Hope this helps! Michael