One Rep Max Calculator - 1RM Calculator

Calculate your one-rep max (1RM) for weightlifting exercises. Find out the maximum weight you can lift for a single repetition based on your current performance.

Understanding Your One Rep Max (1RM)

The One Rep Max (1RM) is the maximum weight you can lift for a single repetition of an exercise. It’s a fundamental metric in strength training used for program planning and progress tracking.

Why is 1RM Important?

Knowing your 1RM helps with:

• Training Programming - Calculating the right weights for different rep ranges
• Progress Tracking - Measuring strength gains over time
• Competition Preparation - Preparing for powerlifting or weightlifting competitions
• Safe Loading - Avoiding overtraining through precise load calculation

Formulas Used

Our calculator provides several proven 1RM formulas:

• Epley Formula - Most widely used, good for 1-10 reps
• Brzycki Formula - Accurate for lower rep ranges (1-7)
• Lander Formula - Conservative estimate
• Lombardi Formula - Good for higher rep ranges

You can estimate your 1RM without actually performing a maximum attempt, which is safer and reduces injury risk.