In boxing and mixed martial arts, fights and fighters come in all weights. The biggest in both sports are heavyweights, and there are weight classes for even the smallest boxers and MMA fighters. In some cases, the divisions are spaced apart by just a few pounds.
In boxing, there are 17 men's weight classes, ranging from heavyweight (no upper weight limit) to strawweight (105 pounds and under). In MMA, there are nine weight divisions for men.
Boxing also has 17 women's weight classes, and MMA has six for women.
In women's boxing, the weight limits can vary depending upon the sanctioning organization. In MMA, not every fight promotion recognizes every division. For example, the UFC does not have a strawweight division for men or atomweight or super atomweight classes for women.
It is not unusual for fighters to move between weight classes. Sometimes, it's a champion opting to pursue a second title in a bigger -- or smaller -- domain. Other times, athletes change divisions because over time it becomes difficult to cut the weight necessary to make their original division's limit.
Here is a rundown of the various weight classes and what each one signifies.