More tools · Fitness
One Rep Max Calculator
Estimate your one-rep max from any weight and rep combination, plus reference training percentages.
How this is calculated
This uses the Epley formula, one of the most common ways to estimate a one-rep max (1RM) from a set of multiple reps: 1RM = weight × (1 + reps ÷ 30). It gets less accurate above about 10-12 reps, since the relationship between reps and strength isn't perfectly linear at higher rep ranges. The percentage table gives reference training weights off that estimate.