Tools/One-Rep Max Calculator
One-Rep Max Calculator
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition. It is used to set training loads as a percentage of your max. Enter the weight you lifted and the number of reps you completed — this calculator applies three established formulas (Epley, Brzycki, and Lander) and shows their average so you get a reliable estimate without performing a true max effort.
About the formulas
Epley (1985): The most widely used formula. Tends to slightly overestimate at higher rep ranges but is accurate from 1–10 reps.
Brzycki (1993): Accurate for sets of 1–10 reps. Gives slightly more conservative estimates than Epley.
Lander: Uses a linear model that performs well across a broader rep range, especially 6–12 reps.
All formulas become less accurate above 10 reps. For the most reliable estimate, test with a weight you can lift for 3–6 reps.