How to Choose Tennis Grips
How to Measure Your Grip Size
To measure your grip size, measure the space from the middle line on your palm to the tip of your ring finger.
As a rule, go with a smaller grip if you're between sizes, because you can always add an overgrip or heat-shrink sleeve. Overgrips will add about 1/16" and heat-shrink sleeves will add about 1/8".
Go find a Grip