One Rep Max Calculator

Calculate your maximum lifting capacity using proven formulas

Select Formula:

Weight Lifted

Number of Reps

📊 Rep Range Chart

What is One Rep Max (1RM)?

Your One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. It's a crucial metric in strength training and powerlifting for tracking progress and programming workouts.

Why Calculate Your 1RM?

• Program Design: Set appropriate training loads (70-85% for strength, 85-95% for power)
• Progress Tracking: Monitor strength gains over time
• Competition Prep: Plan attempts for powerlifting meets
• Safety: Avoid attempting dangerous weights without proper preparation

Formula Explanations

Epley Formula: Most popular and accurate for moderate rep ranges (2-10 reps)

Brzycki Formula: Conservative estimate, good for higher rep ranges

Lander Formula: Slightly more aggressive, good for lower rep ranges

Lombardi Formula: Exponential formula, works well across all rep ranges

How to Use This Calculator

1

Choose Your Formula: Select from Epley (most popular), Brzycki, Lander, or Lombardi formulas. Epley is recommended for most users.

2

Enter Weight: Input the heaviest weight you can lift for multiple reps (ideally 3-8 reps for accuracy).

3

Enter Reps: Input the number of reps you performed with that weight (maximum effort set).

4

Calculate: Click the calculate button to see your estimated 1RM and percentage-based rep ranges.

⚠️ Important Safety Notes:

• This is an estimation - actual 1RM may vary
• Always warm up properly before testing maximum lifts
• Use proper form and have a spotter when attempting heavy weights
• Consider testing 1RM only after adequate training experience