One-rep max calculator: estimate your 1RM and training percentages
Your one-rep max (1RM) is the most you can lift once with good form. You can estimate it from a harder set of a few reps instead of testing it: Epley uses weight × (1 + reps ÷ 30) and Brzycki uses weight × 36 ÷ (37 − reps). Estimates are best from sets of 10 reps or fewer.
- Estimated 1RM
- 91.7 kg
- Epley 93.3 · Brzycki 90.0
| % of 1RM | Load | Typical reps |
|---|---|---|
| 95% | 87.5 kg | 2 |
| 90% | 82.5 kg | 3–4 |
| 85% | 77.5 kg | 5–6 |
| 80% | 72.5 kg | 7–8 |
| 75% | 70.0 kg | 9–10 |
| 70% | 65.0 kg | 11–12 |
| 65% | 60.0 kg | 13–15 |
How it works
Two formulas
Epley and Brzycki agree closely below 10 reps and drift apart above it. The calculator shows both and their average.
Percentages
Strength work is often planned at 75% to 90% of 1RM and hypertrophy work at 65% to 80%. The table rounds to the nearest 2.5.
Questions
Is it safe to test a true 1RM?
It carries more risk than an estimate, especially without a spotter or experience. An estimate from a set of 3 to 6 reps is enough for planning.
Why do the formulas give different numbers?
They were fitted to different groups and lifts. Use one consistently so your progress compares like with like.
Does it work for bodyweight exercises?
Add your bodyweight to the load for exercises like pull-ups and dips, then subtract it from the result.
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Accurate as of November 12, 2026. Training and nutrition guidance only, not medical advice. See a clinician for symptoms, injury or a medical condition.
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