One-Rep Max (1RM) Calculator
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition of a given exercise. Knowing your 1RM helps you program training loads, track strength progress, and compare performance across different rep ranges.
This calculator estimates your 1RM using two well-known formulas — Epley and Brzycki — based on a sub-maximal lift. It also provides a percentage table so you can plan sets at the right intensity for your training goals.
How it works
Epley: 1RM = weight × (1 + reps / 30). Brzycki: 1RM = weight × 36 / (37 − reps). Both formulas are most accurate for rep ranges of 2–10.
Use cases
- Programming training loads based on percentage of 1RM
- Tracking strength progress over time without maximal testing
- Comparing strength across different rep ranges and exercises
- Planning periodized training cycles