Borg RPE Scale Calculator

About this calculator

The Borg Rating of Perceived Exertion (RPE) scale, developed by Swedish psychologist Gunnar Borg, is a 6-to-20 scale that lets someone rate how hard they feel their body is working during exercise, based on physical sensations like breathing rate, muscle fatigue, and sweating rather than a heart rate monitor. The scale's odd 6–20 range wasn't arbitrary — it was designed so that multiplying the RPE value by 10 gives a rough estimate of heart rate in beats per minute for a typical adult during steady-state exercise.

This calculator takes an RPE rating and returns the estimated heart rate, an effort percentage, and an intensity category, following the original Borg design logic. It's widely used in exercise physiology, cardiac rehabilitation, and personal training as a low-cost, equipment-free way to gauge and prescribe exercise intensity — particularly valuable for people on heart-rate-altering medications like beta blockers, where a heart rate monitor alone can be misleading.