There is a separate section on grip size for tennis racquets. You should use this link to view this section.
The Racquet Guide to Grips
All players should understand a few basic facts about grips. The first one is to realise that you do not want the handle of your racquet to slip. This seems obvious, but not all players have a suitable grip fitted to their racquets.
There are two main types of grips, which are described below. Select the type you prefer and use the link for further information.
This is the type of grip that came with your racquet. When they are worn out, you remove the grip and replace it with a new one. These are usually long lasting and economical.
These are a thin material that wraps over the top of the original grip. These grips usually have a softer feel, but need replacing more frequently.