One-Rep Max
Estimate your 1RM and training loads from a lift.
Enter values
kg
—
—
Step by step
The formula
1RM = weight × (1 + reps/30) (Epley)
A one-rep max is the heaviest single lift you could manage. Estimating it from a lighter set avoids the risk of actually testing it. Epley and Brzycki are the two standard formulas; they diverge as reps climb, so this averages them and stays most reliable under about ten reps.
All calculations run locally in your browser and update instantly as you type.
Example calculations
Common questions this calculator answers — select one to load its values.
Related calculators
Frequently asked questions
How reliable is a 1RM estimate?+
Formulas like Epley and Brzycki are most accurate for low rep counts (under ~10). This tool averages both. Always warm up and lift safely.
All calculations run locally in your browser. Nothing you type is sent to a server.