Enter the weight you lifted and the number of reps performed to calculate your 1RM (one-rep max) and estimated reps for different formulas.

## Understanding Rep Max Calculations

The one-rep max (1RM) is the maximum amount of weight that a person can lift for one repetition of a given exercise. The formulas used in this calculator provide estimates based on the number of repetitions and the weight lifted.

### Formulas Used in This Calculator

Each formula estimates your 1RM based on different models and assumptions. These formulas are commonly used in strength training and are referenced as follows:

**Lombardi**: Calculates 1RM using a power model based on repetitions.**Brzycki**: Uses a linear regression model based on repetitions to predict 1RM.**Epley**: Takes both weight lifted and reps performed into account using an additive formula.**Mayhew**: Introduces a regression model for 1RM prediction based on larger datasets of lifters.**O'Conner**: This formula considers a small adjustment factor for higher reps.**Wathan**: Uses a complex model with multiple variables to estimate strength.**Lander**: Similar to Brzycki but uses different assumptions for strength prediction.

### How It Works

The calculator first calculates your estimated 1RM using each of the listed formulas. It then provides rep maxes for 2RM, 3RM, and up to 10RM based on these estimates.

These calculations provide a rough estimate and should be used as guidelines rather than exact predictions. Always consider your actual lifting ability and consult a professional coach when planning your training program.

Suf is a senior advisor in data science with deep expertise in Natural Language Processing, Complex Networks, and Anomaly Detection. Formerly a postdoctoral research fellow, he applied advanced physics techniques to tackle real-world, data-heavy industry challenges. Before that, he was a particle physicist at the ATLAS Experiment of the Large Hadron Collider. Now, he’s focused on bringing more fun and curiosity to the world of science and research online.