Dragon Ball[]
Yamcha (Emperor Pilaf Saga)[]
Power Level: 9
When Yamcha was first introduced he was the first character that proved to be an even match for Goku, nearly defeating him, albeit when the latter was hungry. Which heavily affected the Saiyan child's power level.
Yamcha (21st World Tournament - Red Ribbon Army Saga)[]

Power Level: 15
After the Pilaf Saga, Yamcha went on to live with Bulma in West City and used most of his time to train for upcoming 21st World Martial Arts Tournament in the span of 8 months. Proving to be even less of a match for Jackie Chun than Krillin, Yamcha did not go past the quarter-finals. In the next arc Yamcha makes an appearance toward the end of the Red Ribbon arc, only to realize too late that Goku had already beaten them.
Yamcha (Fortuneteller Baba Saga)[]

Power Level: 20
Yamcha later helps fight Baba's fighters in order to get the last dragon ball, defeating the Invisible Man and then losing to the Mummy. After realizing how far Goku has surpassed him, he decided to train under Master Roshi to improve for the next tournament.
Yamcha (22nd World Tournament)[]

120
He trained under Master Roshi for 3 years and had improved significantly. He was ultimately defeated by Tien Shinhan in the same manner as how Krillin was defeated by Goku. However, Yamcha forced Tien Shinhan to exert much more of his power than the Crane student expected. After the match, he left the arena with a broken leg, reducing his combat effectiveness for the near-future.
Yamcha (King Piccolo Saga)[]
110
With his leg not fully healed, Yamcha's battle prowess was reduced but he still managed to put up a fight against Tambourine who one-shot Krillin. However, he is spared from being killed as well, when King Piccolo instructs Tambourine to abandon his mission of killing the martial artist, in order to hunt down the person who killed one of his other minions.
Yamcha (23rd World Tournament)[]

Power Level: 180
In the 3 years between King Piccolo's reign of terror and the 23rd World Martial Arts Tournament, Yamcha had climbed Korins tower and learned some new techniques. In the tournament, Yamcha faced off against Hero, who was Kami in disguise, but could not match him in hand-to-hand combat so he relied on ki abilities instead. While he managed to catch Earth's guardian off-guard, he was soundly defeated in the end. He then spent the rest of the tournament cheering on his fellow students, particularly Goku against Piccolo.
Dragon Ball Z[]
Yamcha (Raditz Saga)[]

Power Level: 177
After the tournament, Yamcha appeared to have given up fighting to pursue his baseball career. Although he may have gotten a bit rusty he still maintained a majority of his strength. When the Dragon Team learned of the incoming Saiyan threat, Yamcha was summoned along with the others to train with Kami.
Yamcha (Saiyan Saga)[]

Power Level: 1,480
Training with Kami generously improved Yamcha's battle power to a degree that he was initially able to handle a single Saibaman with little effort. However, his overconfidence led him to drop his guard, and enabled the seemingly defeated alien creature to kill him with a kamikaze-style attack.
Yamcha (Frieza Saga)[]

Power Level: 50,000
Training with King Kai alongside his fallen comrades boosted his power significantly. Though he had some initial trouble with the Ginyu force at first, he was able to handily take out Recoome in an anime-only scene. Yamcha would ultimately spend the remainder of the four months he spent there training intensely under the planet's extreme gravity, before being revived by the Namekian dragon balls on Earth.
Yamcha (Trunks Saga)[]

Power Level: 80,000
A year later, he watches with the rest of the cast as Future Trunks turns into a Super Saiyan and kills Mecha Frieza and King Cold. He then waits with the others for Goku's arrival, where he learns of their fates at the hands of the androids afterward. When Goku wishes Bulma a healthy pregnancy, Yamcha presumes that it is the Saiyan's way of encouraging the two to get married.
Yamcha (Android Saga - Perfect Cell Saga)[]

Power Level: 1,600,000
After being warned of the incoming threat of the Androids, Yamcha spends the next 3 years training to prepare, even while suffering the end of his relationship with Bulma, due to her affair with Vegeta. His strength is enough that Dr. Gero (Android #20) initially believes Yamcha is Goku when first encountering him.
Yamcha (Cell Games Saga)[]

Power Level: 2,000,000
Yamcha's power barely changes throughout the Cell Games, as he, Krillin, and Tien pass up on training in the Hyperbolic Time Chamber. Though he initially states his intention of not fighting Cell, due to not being strong enough, he ultimately winds up fighting against the Cell Jrs alongside the other heroes. He is eventually defeated by the Cell Jr he fought, having his arm broken, but is healed soon after Gohan unlocks Super Saiyan 2.
Yamcha (World Tournament Saga - Fusion Saga)[]

Power Level: 1,500,000
Seven years after the defeat of Cell, Yamcha has seemingly retired from the tournament scene, opting not to participate in the 25th World Tournament. He possibly trained passively, but knows he cannot match the strength of the Saiyans, Piccolo, or Android #18. He is eventually killed, along with everyone else on Earth, during the attack of Majin Buu.
Yamcha (Kid Buu Saga)[]

Power Level: 2,500,000
After dying at the hands of Majin Buu, Yamcha returns to the Otherworld, having been allowed to keep his body. While there, he rediscovers his passion for fighting while training with Krillin and several of King Kai's fighters on the Grand Kai's planet. He even manages to beat Olibu, a legendary warrior able to fight on par with a weighted Pikkon.
Dragon Ball Super[]
Yamcha (Battle of Gods - Broly)[]

Power Level: 10,000,000
After being killed along with everyone else on Earth at the hands of Super Buu, Yamcha reengages in training to improve his strength to help defend the Earth. Though he manages to far surpass his former strength, he is still left out of the battle against the forces of a resurrected Frieza and the Tournament of Power.
Yamcha (Galactic Patrol Prisoner Saga - Granolah the Survivor Saga)[]

2 Billion
After Jaco arrives on Earth and warns the Z-warriors of Moro's impending arrival to Earth, along with the galactic criminals the sorcerer recruited upon his escape from the galactic prison, Yamcha is recruited by Krillin to help defend the Earth. Although the Galactic Police officers are initially skeptical of his abilities, Yamcha quickly proves his strength by flying to a nearby city, where he encounters and quickly defeats three magically enhanced criminals all at once. He also reveals that he spent time training with Piccolo and Gohan after being left out of the Tournament of Power.
Super Dragon Ball Heroes[]
Supreme Kai of Time Saga (Ultra God Mission)[]

100,000,000
Despite being stronger in this alternate series, he was still shown unable to fight the likes of Hit in the anime, and was barely able to hold off the death ball of Metal Cooler in the Heroes manga. He was also narrowly rescued from Broly in his Legendary Super Saiyan form by Jiren, who landed between them just before the Saiyan could land his attack.