Surfboard Volume Calculator – The “Guild Factor”
1. Choose your body weight by sliding the lefthand bar.
2. Next, slide the right-hand bar to the perfect volume for your new board by placing the red dot on your desired GF Ratio.
RECOMMENDED GF SHORTBOARD RATIOS:
– Advanced, extremely fit, high performance surfers: RANGE FROM .34gf to.36gf
– Typical fitness with average, to above average skills: RANGE FROM .36gf to .38gf
– Domesticated, lower fitness, desk jobs, and Weekend Warrior surfers: RANGE FROM .38gf to .42gf
– Novice surfers, or surfers with extremely small surf, thick wetsuits or adverse conditions: RANGE FROM .40gf TO .50gf (depending on age, ability and motivation)
*If you’re surfing in warm water and good waves, the lower end of the scale is recommended. If you’re surfing in poor conditions, looking for help in crowded situations, or wearing thick wetsuits, lean towards the higher end of the range that you fall into.
MORE ABOUT GF (GUILD FACTOR)
The “Guild Factor” or “GF” is a concept recently invented by surfer/scientist Whitney Guild, it measures the ratio between a surfers body weight and the volume (in Cubic Liters) of a surfboard. The GF number is the percentage of volume (floatation) to body weight. If a surfer knows their weight, they can scroll up and down the scale to find their recommended volume (keeping in mind skill and fitness). If a surfer knows the volume of their favorite board, or a board that feels too floaty or not floaty enough, they can use the chart to guide him in a better direction. As anything, this is simply another tool to make things easier when choosing a surfboard. Its not a means to an end, and nothing is set in stone. Ultimately, the surfer needs to use what feels best for themself.
EXAMPLE OF PRO RIDERS’ GF%
Kelly Slater: 72kg / 25.3cl – .35gf
Joel Parkinson: 80kg / 27.5cl – .35gf
Kolohe Andino: 75kg / 26.6cl – .35gf
Taj Burrow: 69kg / 24.25cl – .35gf
Mark Occhilupo 88kg / 30.0cl – .35gf