One-repetition maximum estimate
Compare Epley and Brzycki estimates from a completed set of 1–10 repetitions.
How this works
For entered weight w in kilograms and n completed repetitions, the implemented Epley estimate is w × (1+n/30) for 2–10 repetitions. At one repetition the code returns the entered weight directly. The Brzycki comparison is w × 36/(37−n). Both outputs retain kilograms.
Example
The illustration may use different inputs from the reproducible default inputs listed below.
At the defaults, Epley gives 60 × (1+5/30) = 70 kg and Brzycki gives 60 × 36/(37−5) = 67.5 kg. These are comparison estimates, not instructions to lift either weight. With all reset-default inputs, epley estimate: 70 kg.
- Lifted weight (kg)
- 60
- Completed repetitions (1–10)
- 5
- Epley estimate
- 70 kg
Scope and assumptions
Adult informational estimate only, using whole-number repetitions from 1 to 10. These equations do not measure a maximum or establish a safe weight to attempt; exercise type, technique, fatigue and individual differences affect interpretation. Not medical advice or a training recommendation. The one-repetition Epley special case is an implementation convention.
OpenStax — background algebra, not validation of fitness estimates