One Rep Max Calculator

Name: One Rep Max Calculator
Author: Nahlawi Tools

Calculate estimated one-rep max from lifts

ℹ️ About One Rep Max Calculator

Estimate your one-rep max (1RM) from any weight and rep count using the Epley formula: 1RM = Weight × (1 + Reps / 30). Also calculates percentages of your 1RM (50%–100%) for programming warm-up sets and training loads. Essential for strength training program design and progressive overload tracking.

❓ Frequently Asked Questions

How accurate is the one-rep max estimate?▸

The estimate is most accurate for rep ranges of 1–10. Higher rep counts introduce more estimation error. For best results, test with a weight you can lift 2–5 times.

What is the Epley formula?▸

The Epley formula estimates 1RM as: Weight lifted × (1 + number of reps / 30). It is one of the most widely used and validated 1RM prediction equations in strength training.