What is One Rep Max Calculator?
The One Rep Max (1RM) Calculator estimates the maximum weight you can lift for a single repetition of an exercise. It uses validated formulas (Brzycki, Epley, and Lander) to calculate your 1RM based on the weight you can lift for multiple repetitions, providing a safer alternative to actual maximum lift attempts.
How This 1RM Calculator Works
- Weight Input: Enter the weight you can lift with proper form for your working sets, measured in your preferred unit system.
- Repetition Range: Input the number of clean repetitions performed (1-15 reps), as accuracy decreases with higher rep ranges.
- Formula Application: Applies three scientifically-validated formulas (Brzycki, Epley, and Lander) to calculate an averaged 1RM estimate.
- Percentage Calculations: Generates common training percentages based on your estimated 1RM for program design.
The calculator averages results from three established formulas to provide a reliable 1RM estimate. This mathematical approach offers a safer alternative to actual maximum testing, particularly valuable for strength program design and progress tracking.
Practical Applications of Your 1RM
- Design percentage-based training programs with accurate loading
- Track strength progress without maximum testing
- Compare relative strength across different exercises
- Set realistic strength goals based on current capabilities
- Determine appropriate working weights for various rep ranges
While this calculator provides reliable estimates, actual 1RM can vary based on factors like rest, nutrition, technique, and daily readiness. For maximal accuracy, use weights you can lift for 1-5 reps with strict form, and consider consulting strength professionals for technique assessment.