1 Rep Max Calculator
Estimate your 1RM from any weight × reps set, and get training % for strength, hypertrophy, and endurance.
Common rep ranges at this 1RM
Three Formulas Compared
We show Epley, Brzycki, and Lombardi estimates side-by-side. Epley is the most popular; Brzycki is slightly more conservative above 5 reps; Lombardi handles higher-rep sets better.
Frequently Asked Questions
What is a one rep max (1RM)?
The maximum weight you can lift for a single repetition of a given exercise. It's the standard benchmark for strength training.
Which 1RM formula is most accurate?
Epley and Brzycki give very similar estimates for 2–10 rep ranges. Beyond 10 reps, accuracy drops — all formulas overestimate. Use 3–8 rep sets for best results.
What % of 1RM should I train at?
Strength: 80–95%. Hypertrophy: 65–80%. Endurance: below 65%. Use the % table below for specific loads.
How often should I test 1RM?
Every 8–12 weeks for intermediate lifters. Testing too often causes CNS fatigue; infrequent testing misses progress signals.