One-Rep Max Calculator
Estimate your one-rep max from a completed set using the Epley, Brzycki and Lombardi formulas, then compare percentage-based training loads.
Your lift
Your estimates
Enter your lift and tap “Calculate estimated 1RM” to see your estimated one-rep max and training loads.
How the One-Rep Max Calculator Works
A one-rep max, often shortened to 1RM, is the estimated maximum load a person could lift for one repetition of an exercise.
Rather than requiring a maximal lift, this calculator estimates 1RM from a completed set using three established equations: Epley, Brzycki and Lombardi.
Because each formula uses a different mathematical model, the results can vary slightly. FitnessScopes therefore shows the individual estimates, their range and an average estimate rather than presenting a single formula as exact.
How to Use Your Estimated 1RM
Percentage-based training loads are often used to describe relative training intensity. For example, a programme may prescribe work at a percentage of estimated 1RM.
The percentages shown by this calculator are mathematical estimates based on the average calculated 1RM. They do not account for factors such as exercise technique, fatigue, training experience, equipment, exercise selection or day-to-day performance.
Strength estimate disclaimer
This calculator provides an estimate only. Formula accuracy varies by exercise, repetition range, technique and individual training status. Do not attempt a maximal lift solely because a calculator predicts it.