One-Rep Max Calculator
Estimate your 1RM from a weight and reps (Epley formula).
Estimate the most you could lift once, from a set of multiple reps.
The math behind it
Epley formula: 1RM = weight × (1 + reps ÷ 30). Most accurate for reps under ~10.
Worked example
185 lb × 5 reps → ~216 lb.
FAQ
Should I test a true 1RM?
Estimating is safer — true 1RM attempts carry higher injury risk.