One-Rep Max Arena
Estimate your 1RM and see where you rank.
Enter a set you just crushed — weight, reps, lift, sex and bodyweight — and get your estimated one-rep max, a training-load table, and your percentile among lifters your size.
How this is calculated
Methodology & sources
- 1RM formula (Epley): Epley B. (1985), Poundage Chart — equation reproduced in Reynolds et al. (2006), Prediction of One Repetition Maximum Strength, University of New Mexico
- 1RM formula (Brzycki): Brzycki M. (1993), "Strength Testing — Predicting a One-Rep Max from Reps-to-Fatigue", Journal of Physical Education, Recreation & Dance 64(1), 88–90
- Strength standards: Strength Level — community barbell standards; Beginner, Novice, Intermediate, Advanced and Elite correspond to the 5th, 20th, 50th, 80th and 95th percentiles
Privacy — how your data is handled
All math runs in your browser on your device. Nothing you type is sent to a server,
and saved results live only in this browser's local storage. Tools that use live
public data (food databases, weather) request only what they need to display.
👟 Practical toolkit tip — Simple Pocket Pedometer or Wrist Step Counter
Why it helps: Tracking daily step volume (7,500–10,000 steps/day) prevents subconscious NEAT drop-off when you are in a calorie deficit.
Pro tip: A 15-minute brisk walk after dinner adds ~1,600 steps and blunts post-meal blood glucose spikes.