One Rep Max Calculator
Estimate your 1 Rep Max (1RM) based on weight lifted and repetitions performed.
This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Measure Strength Safely
Testing a true one-rep max takes a toll on your central nervous system and carries a risk of injury. This calculator allows you to estimate your max strength using sub-maximal loads (e.g., a weight you can lift 5 times).
Epley Formula
We use the Epley formula, one of the most recognized formulas for estimating 1RM.
1RM = Weight × (1 + Reps/30)
Related Tools
Calculate your recommended daily water intake based on weight and activity level.
Find your target heart rate zones for different exercise intensities (fat burn, cardio, peak).
Estimate the total volume of blood in your body based on gender, height, and weight.