Carles Carrera recently published an excellent article in his blog about measuring the paddle length that best suits you: http://www.carlescarrera.com/2010/04/definitive-guide-for-choosing-your-sup.html. Carles is a guy after my own heart, Stand Up Paddle Surfing fanatic and a motorcycle nut, with an engineering bent. He went about his analysis in a time honored fashion–he built a table of all the recommended methods of determining paddle length using his height as the standard.
I’m going to add some new information to the methods used to determine paddle length at the end of this article, as well as some tips on what to do when you cut your paddle too short, as many so people do.
Here’s a synopsis of the methods that yield the table:
Starboard: flip the paddle upside down, rest the handle on the ground, and where the paddle blade starts to spread from the paddle shaft it should be about eye level.

With the Starboard method this paddle shaft is already two inches too long.
Quickblade: add 8 inches to your overall height for surfing, and 9 inches more for racing/paddling.
Kialoa: add 6-8” for surfing and 10-12” for racing.
The blade of the Quickblade Elite pictured above is 16.5 inches long–so this paddle is about 16″ above my head. Much to long by either Kialoa or Quickblade recommendations.
Laird Hamilton: “Your paddle should be as tall as the reach above your head. If it’s too short you will be reaching forward – if it’s too big you will be reaching too far back. Tip: Raise your arms up as if you were doing a pull up and that should be the height of your paddle.”
David Kalama: recommends the same method as Laird Hamilton.
<img src="http://www.kenalu.com/ [...]