The common limits
The table at the beginning of this guide compares the familiar Unified Rules limits with ONE divisions carrying the same names. The upper limit is decisive: an identical division name can represent a different weight under another ruleset.
The current Unified Rules also recognize atomweight up to 105 lb and additional divisions at 165, 175, 195 and 225 lb. Recognition does not mean every promotion actively operates each class.
UFC, OKTAGON and PFL
UFC runs men’s divisions from flyweight through heavyweight and primarily strawweight, flyweight and bantamweight for women; active divisions can change. OKTAGON’s published CSMMA rules follow the classic Unified limits. PFL defines the divisions used for each tournament or season. The event’s announced class is therefore decisive.
Why ONE divisions are different
Every equivalent ONE division is ten pounds higher: atomweight to 115, strawweight to 125, flyweight to 135 and so on. ONE also requires hydration testing. A ONE flyweight therefore has the same upper limit as a Unified Rules bantamweight.
Title bouts and allowances
Many promotions permit a small allowance in non-title bouts, while championship limits must be met exactly. The regulator and ruleset determine the amount. OKTAGON, for example, states a 0.5 kg allowance for ordinary bouts and none for title or catchweight contests.
What is a catchweight?
A catchweight is a specifically agreed limit outside a standard division. It may be planned from the start or negotiated after a missed weight. It does not create a permanent new weight class.