One Rep Max (1RM) Calculator
Enter a recent heavy lifting set to estimate your peak strength capacity across major compound lifts.
Formula is most accurate for sets under 10 reps.
Strength Progression Targets
| Percent | Weight | Reps |
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How the Epley One Rep Max Formula Works
Attempting to lift your absolute maximum weight (1RM) to failure can be dangerous and increase injury risk on compound movements. Instead, sports scientists use sub-maximal load estimation models to predict peak capacity safely[1].
Nulls Tracker utilizes the **Epley Formula**[2]—the gold standard in powerlifting and athletic training:
1RM = Weight × (1 + Reps / 30)
By determining your theoretical max, you can safely outline specific hypertrophy target sets (e.g. 70-80% of 1RM) to maximize progressive overload[3] week-over-week.
Scientific References
- LeSuer, D. A., McCormick, J. H., Mayhew, J. L., et al. (1997). The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research, 11(4), 211-213.
- Epley, B. (1985). Poundage Chart. Boyd Epley Enterprises.
- Schoenfeld, B. J. (2010). The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research, 24(10), 2857-2872.