Weight Class Jump Calculator

The calculator holds the fighter's power estimate (derived from lean mass) constant across both classes and only changes the denominator — the weight-class limit itself. Moving down to a lower class limit divides that same power estimate by a smaller number, so the power-to-weight change comes out positive; moving up divides by a bigger number, so it comes out negative. It's a mathematical consequence of comparing the same estimated power against a smaller or larger weight allowance, not a claim that cutting weight makes a fighter physically stronger.

The calculator uses a rough linear approximation — average height in cm equals about 100 plus 0.85 times the class weight in kilograms — and then estimates average reach as roughly 1.02 times that average height. These are simplified stand-ins for real anthropometric data across MMA weight classes, useful for a quick directional comparison but not a substitute for actual class-by-class measurements.

The cut-comparison component only contributes up to 20 points either way. Other factors can outweigh an easier cut: moving up to a class where your lean mass is under 85% of the class limit subtracts 10 points for being undersized, and a height/reach disadvantage at the new class pulls the score down separately. The viability score combines all of these factors, so a smaller cut doesn't guarantee a higher overall score.

Cut risk is banded by the new cut's percentage of walk-around weight: safe under 5%, moderate up to 8%, aggressive up to 12%, and dangerous above 12%. An aggressive cut (risk level 3) subtracts 15 points from viability, and a dangerous cut (risk level 4) subtracts a further 20 points on top of that — so crossing from aggressive into dangerous territory costs 35 points combined, reflecting how sharply real injury and performance risk rises past that threshold.