1RM Calculator (One Rep Max)
Estimate your one-rep max from any weight and reps with the Epley formula. Plan training loads for every lift.
About this tool
Estimate your one-rep max in any lift from a set you already did: enter the weight and reps and the Epley formula returns your 1RM plus the percentage used.
It is the standard way to program strength: convert your work sets into percentages, plan progressions, and compare lifts across different rep ranges without failing a maximal attempt.
FAQ
How does the Epley formula work?
1RM = weight x (1 + reps / 30). Lifting 80 kg for 5 reps estimates a 1RM of about 93 kg.
Why does it matter?
It lets you set percentages for structured programs: 75% for volume work, 90% for heavy singles.
Is the estimate safe to test?
Do not attempt a true max without warm-up sets, a spotter and proper technique. The formula exists to avoid max testing.