One Rep Max Calculator

About One Rep Max Calculations

Your one-rep maximum (1RM) is the maximum weight you can lift for a single repetition of an exercise with proper form. It's a cornerstone metric in strength training and powerlifting used to calibrate training intensity. Rather than testing your true 1RM — which carries injury risk — these formulas let you estimate it safely from a submaximal effort. The Epley formula (published in 1985) is the most widely used, while Brzycki's formula tends to give lower estimates for higher rep counts. To complement your strength training, check our Calories Burned Calculator and Protein Calculator.

Training percentage tables are essential for structured programming methods like 5/3/1, Starting Strength, and other percentage-based programs. Lifters typically train in the 70–85% range for hypertrophy, 80–90% for strength, and above 90% for peaking before competition. Using too high a percentage without adequate base fitness dramatically increases injury risk. These calculators are for informational purposes only — always train under appropriate supervision when testing near-maximal loads.