Last updated: July 7, 2026
Quick Definition
Lightweight is a UFC weight class for fighters who weigh between 146 and 155 pounds (66.2 to 70.3 kg). Title fights require both athletes to weigh in at 155 pounds or under, while non-title bouts allow one extra pound.
What is the lightweight weight class in the UFC?
Lightweight is one of the 12 weight classes the UFC uses to match fighters of similar size, covering everyone above the featherweight limit of 145 pounds up to a ceiling of 155. It sits between featherweight and welterweight on the men’s scale.
The 155-pound figure comes from the Unified Rules of MMA, the rulebook first codified by the New Jersey State Athletic Control Board in 2000 and later adopted by athletic commissions across the United States. Weight classes exist so that skill, not size, decides a fight, and every UFC bout is booked within one of them (or at an agreed catchweight).
Fans run into the term constantly. Broadcast graphics, rankings, and title fights all identify fighters by division, and lightweight carries a reputation as the deepest talent pool in the sport. ESPN’s 2024 divisional power rankings rated it the No. 1 weight class in the UFC.
How the weigh-in rules work at 155 pounds
UFC weigh-ins happen the day before a fight, with athletes stepping on the scale between 9 and 11 a.m. local time. In a non-title lightweight bout, each fighter gets a one-pound allowance and can weigh up to 156 pounds. Title fights allow no margin at all.
That single rule has changed careers. At UFC 274 in May 2022, champion Charles Oliveira weighed in at 155.5 pounds, half a pound over the championship limit, and was stripped of the title before the fight began. He beat Justin Gaethje the next night, but the belt stayed vacant.
A fighter who misses weight in a regular bout usually forfeits a percentage of his purse to his opponent, agrees to a catchweight, or sees the fight cancelled. The number on the scale rarely matches fight-night reality, though. Most lightweights shed water weight during fight week to reach 155, then rehydrate over the next 24 hours and enter the Octagon considerably heavier.
Lightweight in the UFC vs. boxing and other promotions
The word “lightweight” means something different depending on where you hear it.
| Organization or sport | Lightweight limit |
| UFC (MMA) | 155 lb (70.3 kg) |
| Bellator and PFL (MMA) | 155 lb (70.3 kg) |
| Boxing | 135 lb (61.2 kg) |
| ONE Championship (MMA) | 170 lb (77.1 kg) |
The boxing gap causes the most confusion. A boxing lightweight weighs no more than 135 pounds, a full 20 pounds under the UFC limit, so the two sports use the same name for athletes of noticeably different sizes.
ONE Championship’s number looks strange for a different reason. After 21-year-old fighter Yang Jian Bing died from a dehydration-related weight cut in 2015, the Singapore-based promotion banned cutting by dehydration and set its divisions around a competitor’s walking weight, which pushes every limit upward. The UFC and most American promotions stick to the Unified Rules figure of 155.
Where lightweight sits among the UFC’s weight classes
The eight men’s divisions span 125 to 265 pounds.
| Division | Upper limit |
| Flyweight | 125 lb |
| Bantamweight | 135 lb |
| Featherweight | 145 lb |
| Lightweight | 155 lb |
| Welterweight | 170 lb |
| Middleweight | 185 lb |
| Light heavyweight | 205 lb |
| Heavyweight | 265 lb |
The gaps matter. Each of the four lightest divisions is separated by 10 pounds, but the step from lightweight up to welterweight is 15. A lightweight moving up gives away real size against naturally bigger men. Islam Makhachev made that jump successfully, vacating the lightweight title and then winning the welterweight belt at UFC 322 in November 2025 to become a two-division champion, per ESPN.
Lightweight also carries a large share of the roster’s activity. According to Martial Nerd, welterweight, lightweight, middleweight, and light heavyweight together account for over half of all UFC fights.
A short history of the division
The UFC first split fighters by weight at UFC 12 in 1997, and the original “lightweight” class included anyone under 200 pounds. The label moved around in the years that followed. When the promotion adopted the Unified Rules weight classes at UFC 31 in May 2001, the modern 155-pound division took shape; its title had been called the bantamweight championship before the change, per Wikipedia’s championship records.
The division went dormant after UFC 49 in 2004 and returned at UFC 58 in 2006. Sean Sherk beat Kenny Florian at UFC 64 to become the first lightweight champion of the revived era.
Since then, the belt has passed through some of the biggest names in MMA. Conor McGregor knocked out Eddie Alvarez at UFC 205 in November 2016 to become the first fighter to hold two UFC titles at the same time. Khabib Nurmagomedov retired in 2020 as champion with a perfect 29-0 record. Islam Makhachev set the divisional record with four consecutive title defenses before moving up in weight. As of July 2026, Justin Gaethje holds the title after stopping Ilia Topuria at UFC Freedom 250 on June 14, 2026, a fight Topuria’s corner ended after the fourth round.
Frequently Asked Questions
What is the UFC lightweight limit in kilograms?
70.3 kg. The full divisional range runs 66.2 to 70.3 kg, or 146 to 155 pounds.
Who is the current UFC lightweight champion?
Justin Gaethje, as of July 2026. He won the undisputed title by stoppage over Ilia Topuria at UFC Freedom 250 in Washington, D.C.
Is a UFC lightweight the same as a boxing lightweight?
No. Boxing caps its lightweight division at 135 pounds; the UFC caps it at 155. The shared name refers to two different sizes of athlete.
How much do lightweights actually weigh on fight night?
More than 155. Fighters rehydrate after the weigh-in and typically enter the cage well above the limit, with the exact amount varying by athlete.
Sources
- UFC. “Understanding UFC Weight Classes.” Accessed July 7, 2026.
https://www.ufc.com/news/understanding-ufc-weight-classes-and-weigh-ins - Wikipedia. “Lightweight (MMA).” Accessed July 7, 2026.
https://en.wikipedia.org/wiki/Lightweight_(MMA) - Wikipedia. “List of UFC champions.” Accessed July 7, 2026.
https://en.wikipedia.org/wiki/List_of_UFC_champions - Wikipedia. “Mixed martial arts weight classes.” Accessed July 7, 2026.
https://en.wikipedia.org/wiki/Mixed_martial_arts_weight_classes - ESPN. “Current and all-time UFC champions.” Accessed July 7, 2026.
https://www.espn.com/mma/story//id/14947566/current-all-ufc-champions - ESPN. “UFC weight class power rankings.” Accessed July 7, 2026.
https://www.espn.com/mma/story//id/40173563/ufc-weight-class-power-rankings-lightweights-claim-top-spot-islam-makhachev-dustin-poirier - CBS Sports. “UFC White House results: Justin Gaethje scores stunning upset of Ilia Topuria to claim world title.” Accessed July 7, 2026.
https://www.cbssports.com/ufc/news/ufc-white-house-live-updates-results-freedom-250-highlights-ilia-topuria-justin-gaethje/live/ - Martial Nerd. “All the UFC Weight Classes and Fighter Divisions.” Accessed July 7, 2026.
https://www.martialnerd.com/posts/mens-and-womens-ufc-weight-classes
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