Many players ask about how thick their handle should be on the badminton racket – this can be altered by using grip tape.
There is no specific formula for calculating grip size. Really, it is down to experimentation! The grip needs to be large enough for your to hold the racket comfortably with a relaxed grip. If you find yourself having to tightly clench the racket to keep control, then your grip is likely to be too small.
Your grip should be small enough that you can make use of grip tightening for power – if the grip is so big that it fully fills your palm, then your tightening grip will not be as effective. Having a very thick grip will make your grip less flexible too.