Volume is useful, but it is only one measurement in a complex design. For most surfers, a difference of 0.2 to 0.5 litres is far less important than the board’s width, rocker, foil, rails and foam distribution.A practical starting pointFor an average-to-advanced surfer choosing a performance shortboard, Rusty suggests converting body weight to kilograms and multiplying by roughly 0.33 to 0.35. Ability, fitness, age and wave type may all justify increasing that number. Treat the result as a starting range, not an instruction carved in stone.Why the decimal is misleadingComputer volume is normally calculated from the cut blank. Hand-finishing removes material, so the finished board will not match the digital number perfectly. Your body weight also changes through the day by a greater percentage than the small volume differences many surfers worry about.Decide whether thickness or litres is your priority, then let the shaper balance the rest. Subtle adjustments to rocker, deck contour, fins and glassing can affect performance much more than chasing another fraction of a litre.Adapted with permission from Rusty Surfboards USA.
