A one-rep max (1RM) represents the maximum load you can lift for a single repetition. Predication formulas are highly validated in sports science (e.g. published in the Journal of Strength and Conditioning Research) to prevent injury risks during testing.
Formula Comparisons
| Formula Name | Calculation Type | Best Suited For |
|---|---|---|
| Epley Formula | Linear approximation. | General lifting and moderate rep ranges (3–8 reps). |
| Brzycki Formula | Linear divisor model. | Lighter weights and slightly higher reps (5–10 reps). |
| Lander Formula | Curved quadratic model. | Heavy loads and low rep sets (2–5 reps). |
| Lombardi Formula | Power function scaling. | Highly explosive lifts and advanced athletes. |
How to use the fitness result
Fitness calculators work best when you track trends, not just single-day numbers. The goal is to turn the output into a training, nutrition, or body-composition decision.
- Recheck after a meaningful training block or bodyweight change.
- Use the result alongside performance, recovery, and waist or body-fat trends.
- Compare multiple formulas when the calculator offers more than one estimate.
For this calculator in particular, use the output as a practical benchmark for training age, body composition, and benchmark comparisons. If the result looks off, check measurement technique first, then formula choice, then the unit mode.
As a rule, recalculate after a meaningful change in training load, diet, sleep, bodyweight, or performance. That keeps the number relevant without chasing noise.