One Rep Max Calculator

Calculate your one-repetition maximum using proven formulas. Get personalized training load recommendations and rep range charts for optimal strength development.

Ready to Calculate

Enter your lift details and click "Calculate 1RM" to get your estimated one-rep maximum and training recommendations.

Estimated 1RM
Formula Comparison
Rep Range Chart
Training Loads

1RM Calculator Guide

Your one-rep maximum (1RM) is the heaviest weight you can lift once with proper form. Use it to design training programs, track progress, and train at the right intensity for your goals.

Which Formula to Use

Brzycki: Best for 1-7 reps (most accurate for powerlifting)

Epley: Best for 8-15 reps (most commonly used)

O'Conner: Good middle ground for 5-10 reps

Lombardi: Conservative estimates (good for beginners)

Important: These are estimates that can vary ±5-10%. Calculate when fresh, use proper form, and test actual 1RMs progressively with spotters. Results are specific to each exercise.