One Rep Max Calculator
Estimate your max lift from any rep range
Calculator
Calculate Your 1RM
Enter the weight you lifted and how many reps to estimate your one rep max.
Frequently Asked Questions
How accurate are 1RM calculators?
Most accurate with 1-10 reps. Above 10 reps, the formulas become less reliable because muscular endurance becomes a bigger factor. For best results, use a weight you can do for 3-5 reps.
Should I actually attempt a 1RM?
Only if you have proper form and a spotter. For most people, estimating from a 3-5 rep set is safer and nearly as accurate. Save true 1RM attempts for competition or periodic testing.
One Rep Max Calculator
Estimate your one rep max (1RM) using the Epley, Brzycki, and Lombardi formulas. See percentage-based training loads.