Fighter Size Comparison Tool
Compare two fighters' weights side-by-side. Instantly see each fighter's boxing weight class, the exact difference in lbs and kg, and whether it's a fair matchup or a step-up.
Fighter Size Comparison
How to use the comparison tool
Pick your unit (lbs or kg), then type each fighter's weight. The tool maps each weight to the closest recognised professional boxing division (Minimumweight up to Heavyweight), calculates the size difference, and shows a visual bar so you can see the gap at a glance.
Use it to sanity-check upcoming fight announcements, evaluate catch-weight bouts, or compare two fighters from different eras to see how they would have stacked up by size.
Frequently asked questions
Enter each fighter's weight in lbs or kg. The tool determines each fighter's professional boxing weight class, calculates the weight difference, and tells you whether it's a fair fight (same class) or a step-up (different classes).
A step up is when two fighters fall into different recognised divisions. Even one pound across a division boundary technically moves a fighter into a new class, but most commissions accept catch-weight bouts within a few pounds of either limit.
Weight is one of the strongest predictors in boxing because mass translates to punch force, but reach, speed, conditioning, experience and style matter too. The tool only compares size — not skill.
Looking for the full division reference? See the complete weight classes chart or the Top 15 Pound-for-Pound rankings.