Health & Fitness
One Rep Max (1RM) Calculator
Enter the weight and reps you lifted to estimate your one-rep max and training loads.
For information only. Results are estimates and are not medical advice. Please talk to a doctor or qualified professional about your own health.
About the One Rep Max (1RM) Calculator
Different formulas (Epley, Brzycki, Lombardi) give slightly different values. The calculator averages them for a steadier estimate.
Estimates are most accurate with sets of 2–10 reps. Never test a true max without a spotter and a proper warm-up.
Frequently asked questions
What percentage of 1RM should I train at?
Roughly 65–75% for 8–12 reps (muscle size), 80–90% for 3–6 reps (strength).
How often can I test my 1RM?
Use estimates regularly; test a true max rarely, a few times a year at most.