One Rep Max Calculator
Training 1RM from a submaximal set — not a tested max. Click any i for detail.
Set
Weight
i
Weight lifted
Load on the bar (same units you train in). |
|
|---|---|
Reps
i
Repetitions
Completed reps. Formulas get noisy above ~10–12. |
How to use this calculator
- Enter the weight you actually lifted.
- Enter clean reps (no grind-fest).
- Read Epley as the headline and Brzycki as a second estimate.
- Use 50–90% of 1RM for working sets if that is your program.
Results explained
Epley: 1RM = weight × (1 + reps/30). Brzycki: weight × 36 / (37 − reps). They diverge as reps rise.
Quick reference: 1RM percents
Percents are program conventions, not physiology.
| Item | Detail |
|---|---|
| 5 reps (Epley) | ~1.17 × weight |
| 8 reps (Epley) | ~1.27 × weight |
| Epley vs Brzycki | Brzycki is often a bit lower at mid reps |
| >12 reps | Treat as a very rough ceiling |
Fatigue, range of motion, and pause vs touch-and-go change the real max.
How the estimate is built
Epley 1RM = w(1 + r/30); Brzycki 1RM = w·36/(37−r).
Example scenario
185 × 5 → Epley 216 (185 × 1.167).
FAQ
Barbell vs machine?
The algebra is the same. The prediction is worse on machines with odd strength curves.
Why two formulas?
No single equation fits everyone. The spread is part of the answer.
Bodyweight?
Add it only if the movement includes you as load (e.g. some weighted pull-up math).