One Rep Max Calculator
Estimate your one-rep max (1RM) and get a complete percentage chart for programming your training.
Enter a weight you can lift for multiple reps (ideally 2-10 reps).
kg
reps (1-12)
How This Calculator Works
This calculator uses the average of five validated formulas (Brzycki, Epley, Lander, Lombardi, O'Conner) to estimate your one-rep max from submaximal performance.
Best accuracy: Use weights you can lift for 2-6 reps. Higher rep ranges (10+) become less accurate as muscular endurance plays a larger role.
Safety note: These are estimates. When actually testing your 1RM, always use a spotter and start conservatively.