# Wathan

> 1994

- Equation: `1RM = 100 × w / (48.8 + 53.8 × e^(−0.075 × r))`
- Variables:
  - `w`: Load lifted, same unit as the 1RM.
  - `r`: Repetitions completed.
  - `e`: Euler’s number.
  - `1RM`: Estimated one-repetition maximum.
- Authors: Wathen, D.
- Source: Essentials of Strength Training and Conditioning, Human Kinetics, pp. 435–439
- DOI: None

Commonly called Wathan; the original author is Wathen.