Safety and interpretation
One-rep max formulas are estimates. They become less reliable at high rep counts and do not account for technique, fatigue, exercise type or spotting conditions.
Example
If you lift 100 kg for 5 reps, the Epley estimate is 100 x (1 + 5 / 30) = about 116.7 kg. Brzycki gives a similar but not identical estimate.
Common mistakes
Do not test a true one-rep max without appropriate experience, warm-up, equipment and spotting. High-rep sets can overstate or understate real max strength.
Limitations
This is not medical or coaching advice. It does not account for injury risk, exercise selection, fatigue, range of motion or individual strength profile.
Last reviewed: 2026-05-17