The number of rounds varies and is predetermined by the management and promoter. It is normally between 4 and 12 rounds in professional boxing, and is based on the age and experience of the boxers, and whether or not it is a title fight.
A young or generally inexperienced professional boxer will typically start their pro career fighting 4 rounds. As they progress, and their conditioning improves, the number of rounds increases. Usually to 6, 8 and then 10 rounds. Most non-title fights are 10 rounds for accomplished contenders.
Title fights are normally 12 rounds, the maximum number allowed. Some title elimination fights or other main event fights may also be 12 rounds. The final two rounds being known as the ‘championship rounds’.
Historically, boxing was less regulated and often bouts could go on indefinitely, until there was a clear winner. A maximum number of 15 rounds was introduced, along with other rules to improve safety, when the Queensbury rules came into use. This was later revised down to 12 due to concerns over the damage caused by long duration boxing, especially with regard to dehydration an fatigue.
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