One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. It's a standard measure of strength in weight training and helps athletes determine their training intensities.

Knowing your 1RM helps you determine appropriate training weights for different rep ranges, track strength progress over time, set realistic goals, and design effective workout programs tailored to your current strength level.

Our calculator uses multiple scientifically validated formulas (Brzycki, Epley, Lombardi, Mayhew, O'Conner, Wathan) and provides an average for maximum accuracy. For most individuals, the calculated 1RM is within 2-5% of their actual tested maximum.

Testing your actual 1RM should only be done with proper form, after adequate warm-up, and preferably with a spotter. Beginners should avoid 1RM testing until they've developed proper technique and base strength. Always consult with a fitness professional if you're unsure.