Winning percentage can be calculated by dividing the number of wins by the total number of games played. The percentage can be displayed as a decimal less than or equal to 1, or as a percentage between 0 and 100 percent.
If the number of wins and number of losses are known, the total number of games can be derived by adding the number of wins and number of losses. If ties are also possible, then the total number of games is the sum of wins, losses and ties.
If ties are not possible, dividing the number of wins by number of games played calculates the winning percent in decimal form. If ties are possible, then a tie typically counts as half a win and half a loss. In such a case, the winning percentage is equivalent to (number of wins + 1/2 * number of ties) / total games played.
To derive winning percent as a percentage between 0 and 100 percent, multiply the result by 100 percent. For example, if a team won 10 games and lost 15, then its winning percentage would be 10 / (10+15) = .400, or .400 * 100% = 40%.