A team needs 13 rounds to win a standard Valorant match.
Standard Competitive and Unrated matches use a first-to-13 format. Teams begin on opposite sides, attack or defend for 12 rounds, then switch sides at halftime. The first team to reach 13 round victories wins, so a match can finish as quickly as 13–0 or continue much longer if the score stays close.
At 12–12, standard matches enter overtime rather than ending in a draw. Overtime rules can include alternating attack and defense rounds, and teams must satisfy the mode’s overtime win conditions. This is why 13 is the normal answer even though a match may contain more than 24 total rounds. Other formats, such as Swiftplay, Spike Rush, and special limited-time modes, use different round targets and should not be used to answer the standard-match question.