How many justices are needed for a majority decision on the Supreme Court?

In the context of the United States Supreme Court, a majority decision requires at least five justices to agree on a ruling when the court consists of nine justices in total. The Supreme Court typically has an odd number of justices to avoid tie votes, which would leave cases unresolved. Therefore, since five justices represent more than half of the nine, their agreement is sufficient to establish a majority and render a definitive ruling on a case. This principle is fundamental in ensuring that decisions can be reached efficiently while maintaining clear legal precedents.