Your five-rep max (5RM) is the maximum weight you can lift for five consecutive repetitions. It's a cornerstone metric in many strength training programs because it represents a sweet spot between pure strength (like a 1RM) and muscular endurance. Training with and around your 5RM is highly effective for building strength and muscle mass. This calculator helps you estimate your 5RM without having to perform a risky max-out set, using your performance from a set with a different rep count.