Wetsuit Buoyancy Calculator

Improvement % is calculated purely from Wetsuit Thickness and Body Weight -- it represents how much faster the suit's buoyancy lets you move as a percentage of your effort, and that percentage doesn't depend on how fast you already swim. Swim Pace only comes into play once that percentage is converted into an actual time, in Estimated Pace with Wetsuit and Pace Improvement.

Wetsuit Thickness sets the base buoyancy benefit directly, contributing roughly 1.2% per millimeter (with diminishing returns above 3mm), while Body Weight only adjusts that base benefit up or down by a modest scaling factor for how much a swimmer's build affects their baseline body position. Across the calculator's full input ranges, Wetsuit Thickness moves Improvement % far more than Body Weight does.

Very thick neoprene keeps adding buoyant lift, but each additional millimeter contributes somewhat less usable benefit while increasingly restricting shoulder rotation and stroke mechanics, so this calculator applies a reduced rate above 3mm rather than assuming benefit keeps climbing at the same pace indefinitely. This mirrors why most triathlon wetsuits max out around 5mm even in cold water, rather than using thicker neoprene throughout.

Without a wetsuit, a heavier swimmer's hips and legs tend to sit slightly lower in the water, creating more drag from a less horizontal body position. A wetsuit's buoyancy corrects more of that sag for a heavier swimmer than for a lighter one who was already riding relatively high, so this calculator scales the improvement percentage up modestly as Body Weight increases.

These multiply your per-100m Pace Improvement by the number of 100m segments in each distance -- 1000m for a straightforward pool-length comparison, 1500m for an Olympic-distance triathlon swim, and 3800m for a full Ironman-distance swim -- so you can see the same underlying buoyancy benefit scaled to a specific race or training distance you actually care about.