Estimate your one-rep maximum for any exercise without having to attempt a true max lift. Enter the weight you lifted and how many reps you completed — the Brzycki formula does the rest and gives you a full loading table.
1–15 reps (Brzycki formula)
Your 1RM is the foundation of percentage-based strength programming. Different percentages target different adaptations — strength, hypertrophy (muscle growth), or muscular endurance. Most programs prescribe sets at 65–85% of 1RM, where the rep ranges fall naturally between 5 and 15.
The Brzycki formula (1RM = weight ÷ (1.0278 − 0.0278 × reps)) is most accurate for 1–10 reps. Beyond 12 reps, the estimate becomes less reliable because fatigue factors and muscle fiber recruitment patterns shift significantly.
| % 1RM | Est. Reps | Training Goal | Example Sets |
|---|---|---|---|
| 90–100% | 1–3 | Max strength | 3×1, 5×1 |
| 80–89% | 4–6 | Strength | 4×4, 5×3 |
| 70–79% | 8–12 | Hypertrophy | 3×10, 4×8 |
| 60–69% | 12–15 | Hypertrophy+ | 3×12, 4×12 |
| 50–59% | 16–20 | Muscular endur. | 3×20 |