One-Rep Max Calculator
Estimate 1RM from a training set via Epley and Brzycki.
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Introduction
One-Rep Max Calculator — Estimate 1RM from a training set via Epley and Brzycki. Enter Weight lifted, Reps completed to get an instant, accurate result.
Formula
Epley: weight × (1 + reps/30). Brzycki: weight × 36 / (37 − reps).
Step-by-step
- Enter the Weight lifted.
- Enter the Reps completed.
- Click Calculate to see your result instantly.
Real-world example
Example: With Weight lifted = 100, Reps completed = 5, the One-Rep Max Calculator gives Epley: 116.6667, Brzycki: 112.5.
Frequently Asked Questions
Why two different formulas?
Epley and Brzycki are both widely used estimation formulas that can give slightly different results, especially at higher rep counts — showing both gives a useful range.
How accurate is an estimated 1RM?
It's most accurate for sets of around 2-10 reps; estimates get less reliable at very high rep counts.
What inputs does the One-Rep Max Calculator need?
You'll need to provide: Weight lifted, Reps completed. All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.
How accurate is the One-Rep Max Calculator?
The One-Rep Max Calculator applies the formula exactly as calculated — Epley: weight × (1 + reps/30). Brzycki: weight × 36 / (37 − reps). — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.
Is this a medical diagnosis?
No. The One-Rep Max Calculator provides an estimate based on standard formulas and general population data, not a medical diagnosis or personalized clinical advice. Individual results can vary — consult a doctor or other qualified healthcare provider for medical concerns.
Is the One-Rep Max Calculator free to use?
Yes, the One-Rep Max Calculator is completely free, requires no signup, and runs instantly in your browser.
About the One-Rep Max Calculator
The One-Rep Max Calculator uses a real, verifiable formula — Epley: weight × (1 + reps/30). Brzycki: weight × 36 / (37 − reps). — so results are accurate every time, not an approximation.