One Rep Max Calculator

Calculate your One Rep Max (1RM) instantly — right from your browser.

Whether you're preparing for a powerlifting competition or planning your next training cycle, knowing your true max is essential. This extension helps you estimate your one rep max for Bench Press, Squat, and Deadlift using proven scientific formulas.

How It Works:
Simply enter the weight you lifted and the number of reps you completed. The calculator uses two time-tested methods (Epley and Brzycki) to give you an accurate estimation.

What You Get:
🏋️ Dedicated modes for Bench Press, Squat, and Deadlift
📐 Accurate calculations using Epley and Brzycki formulas
📊 A full percentage breakdown chart for programming your workouts
💾 Auto-save feature that remembers your last input

Perfect For:
- Strength athletes planning training percentages
- Lifters tracking progress over time
- Coaches programming for clients

All data stays on your device — we don't collect or transmit any information. Clean, fast, and free.