Surfboard Fin Size Guide Calculator
Find the right surfboard fin size for your weight, surf style, and board type.
Get base, height, and rake recommendations for single, thruster, and quad setups.
Recommended Fin Size
Surfboard Fin Sizing
Fin size is primarily determined by surfer weight, with adjustments for surf style and wave conditions.
Key fin dimensions:
- Base (mm): Width of the fin at the board. Wider base = more drive and speed. Narrower = more pivot and release.
- Height/Depth (mm): How deep the fin extends into the water. More depth = more hold and stability. Less = more loose feeling.
- Rake/Sweep: How far the tip sweeps back. More rake = longer, smoother turns. Less rake = more pivoty, responsive.
- Foil: The cross-section shape. Inside foil = lift and speed. Flat inside = more drag but control.
Fin size by surfer weight (thruster side fins, FCS/Futures medium)::
- Under 130 lbs (59 kg): XS/Small — base ~110-115mm, height ~115-120mm
- 130-170 lbs (59-77 kg): Small/Medium — base ~115-120mm, height ~118-125mm
- 170-200 lbs (77-91 kg): Medium/Large — base ~120-125mm, height ~123-130mm
- Over 200 lbs (91 kg+): Large/XL — base ~125-130mm, height ~128-135mm
Larger, stiffer fins provide more control. Smaller, flexible fins increase speed and flow.