Bench Press Calculator — Estimate Your One-Rep Max

Lifted 100 kg for 5 reps and wondering what your max is? Enter any weight and rep count to estimate your one-rep max (1RM) instantly.

🏋️ One-Rep Max Estimator

How the bench press calculator works

The calculator averages two classic strength formulas:

  • Epley: 1RM = weight × (1 + reps/30)
  • Brzycki: 1RM = weight × 36 / (37 − reps)

Both are most reliable when your test set is between 1 and 10 reps. Beyond 12 reps, estimates become less accurate.

Why use our bench press calculator?

LaCalc’s bench press calculator is free, fast, and private. No sign-up, no downloads — type your numbers and get instant results. Every calculation runs in your browser, so your data never leaves your device.

Frequently asked questions

What is a one-rep max (1RM)?
Your 1RM is the maximum weight you can lift for a single repetition. It is the standard measure of maximal strength.
How accurate are 1RM estimates?
Within a few percent for most lifters when based on sets of 1–10 reps. Individual variation, fatigue, and technique all play a role.
Should I test my true 1RM?
Estimates are safer. True 1RM testing needs proper warm-up, spotters, and experience. Beginners should avoid max attempts.

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