1RM Calculator (One Rep Max)
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The 1RM Calculator estimates your one-rep max from a submaximal set by applying several validated 1RM formulas (Epley, Brzycki, Lombardi, O’Conner, Mayhew, Wathan). Enter the weight you lifted and the reps performed; we show each formula’s estimate, the average 1RM, and a Training Max (90% of 1RM) commonly used in programs.
Use the percentage table to plan working sets (npr. 70–85% 1RM za snagu i hipertrofiju). The tool supports metric & US units (kg/lb) and prints loads in both for quick plate math.
FAQ
- How do I estimate 1RM safely?
Use a hard but submax set (≤10 reps) with good form, then calculate 1RM here instead of maxing out every session. - Which formula should I trust?
They’re all approximations; Epley and Brzycki are popular for 3–10 reps. Compare several and use the average. - What is Training Max?
It’s usually 90% of 1RM, used for sustainable progressions and fatigue management. - Why do results differ by lift?
Leverages, technique and rep tolerance vary across bench, squat, deadlift i sl.—očekuj male razlike među formulama. - How often should I update 1RM?
Posle ciklusa (4–8 nedelja) ili kad primetiš jasan napredak u radnim težinama.
Disclaimer
Strength calculations are estimates for training and education and are not a substitute for coaching. Use proper technique, safety equipment and spotters where applicable.
References
- Epley B. Practical strength training load prescription (commonly cited field equation).
- Brzycki M. (1993). Strength Testing—Predicting a One-Rep Max from Reps-to-Fatigue.
- Mayhew JL et al. (1992). Bench press 1RM prediction from submax reps.
- Wathan D. (1994). Load estimation for 1RM using exponential model.