List of boxing weight classes

A weight class is a measurement weight range for boxers. The lower limit of a weight class is equal to the upper weight limit of the class below it. The top class, with no upper limit, is called heavyweight in professional boxing and super heavyweight in amateur boxing. A boxing match is usually scheduled for a fixed weight class, and each boxer's weight must not exceed the upper limit. Although professional boxers may fight above their weight class, an amateur boxer's weight must not fall below the lower limit. A nonstandard weight limit is called a catch weight.

A professional boxer usually weighs more between fights than at the time of a fight. Part of the process of training for a bout is "getting down to fighting weight". The weigh-in takes place the day before the fight. Boxers typically stand on the scales barefoot and without gloves. The weigh-in is often a photo opportunity and boxers or their entourage may trash talk each other. This element is such a valued part of the build-up that heavyweight boxers go through the ritual of being weighed even though there is no limit to be measured against.

A boxer who is over the weight limit may strip naked to make the weight if the excess is minimal; otherwise, in a professional bout, one can try again later, typically after losing weight in the interim through dehydration by vigorous exercise in a steam room. If the excess weight is too great, the effort expended trying to "make weight" will make the boxer unfit for the fight itself. In such cases, the fight may be cancelled, with the over weight boxer sanctioned; or the fight may proceed as a catch weight non-title fight.

The International Boxing Federation (IBF) has a unique weigh-in policy in title fights. In addition to making the weight at the official weigh-in the day before the fight, the boxers are required to submit to a weight check on the morning of the fight. During this later weigh-in, the fighter must weigh no more than 10 pounds (4.5 kg) above the weight limit for the fight. If a boxer skips the morning weigh-in, or fails to make weight at that time, the fight can still proceed, but the IBF title will not be at stake. In heavyweight title fights, the second weigh-in is still mandatory, but since there is no upper weight limit in that class, a boxer can only be sanctioned for failing to submit to the weigh-in.

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