What do extra numbers like K13 or K12 mean on skateboard deck sizes?

Question: What do extra numbers like K13 or K12 mean on skateboard deck sizes?

I received this e-mail - "I know nothing about it and am trying to figure out size/shape terminology. What does it mean when a board says it is "7.37 143-k13". I have searched the web to try and find out what all of the above means without any luck. I know the "7.37" is the width of the board but the "143-k13" is still a mystery to me."

Great question! A lot of online skate shops will simply show you a picture of a board, with the width, and then some random other numbers. When you see something like this 143-k13, what does it mean?

Answer: Well, the first thing it means is that you are looking at a Skate One board (Skate One makes Powell, Powell Peralta, Surf One, MiniLogo, Golden Dragon and Positiv boards). This is their method for telling you the shape of the skateboard deck you are looking at.

This first number tells the shape of the skateboard deck. Skate One Manufacturing has numbered each shape (the "Shape" of a skateboard includes it's concave, width, length, wheelbase, and the length of the nose and tail). They have numbered every single combination that they sell. You can look at this chart on the Skate One website.

The "K13", or K - some other number, refers to the concave. But what does that mean? Well, the concave is how much the skateboard bows in in the middle of the deck. Skateboards aren't usually made totally flat - they are built with concave. This makes them a lot stronger, and gives them more pop.

The letter "K" means that it likely looks like a regular skateboard, and the higher the number, the deeper the concave. An "s" after the number (for example "K12s") is a shorter skateboard, made for smaller skaters. You can see an entire Chart of Skate One Concaves.

This should help you understand a bit better what you are looking at when you see these letters and numbers listed with skateboards you are thinking about buying.