The formulas
- Epley: 1RM = w × (1 + reps ÷ 30) — accurate up to about 10 reps.
- Brzycki: 1RM = w × 36 ÷ (37 − reps) — slightly lower at high reps.
- Lombardi: 1RM = w × reps0.10 — the most optimistic of the three.
All three are estimates from submaximal sets. Accuracy drops as reps increase, so keep your test set at 8 reps or fewer, and stop 1–2 reps short of failure for a cleaner estimate.
Rep-max table
The table below uses your estimated 1RM with standard percentage guidelines, so you can plan working sets without testing a true max. As a safety rule: never attempt a true 1RM alone, and always use collars or a spotter on pressing movements.