One Rep Max Calculator

Understanding Your One-Rep Max

The one-repetition maximum (1RM) is the absolute most weight you can lift for a single repetition of a given exercise. It is a popular measure of strength in weight training. Knowing your 1RM can help you to design effective training programmes and track your progress over time, and the NHS recommends strength training as part of a balanced exercise routine. While directly testing your 1RM can be risky and requires proper preparation, you can estimate it safely using formulas based on the weight you can lift for multiple repetitions. This calculator, provided by Calculator Site, uses several well-regarded formulas to give you a comprehensive estimate.

Our calculator employs three different formulas to estimate your 1RM: the Epley, Brzycki, and Lombardi formulas. Each uses a slightly different mathematical approach, which is why they may produce slightly different results. By providing the average of these three, we offer a balanced and more reliable estimate of your true one-rep max. This allows you to tailor your workouts more precisely, whether you are aiming for strength, hypertrophy, or endurance. Remember to always use a spotter and proper form when attempting lifts close to your maximum capacity. To ensure your nutrition supports your training, try our TDEE Calculator to find out how many calories you need each day.