Free One Rep Max Calculator
Calculate your one-rep max (1RM) and get a complete percentage table for your strength training program.
Calculate Your One Rep Max
Your Results Will Appear Here
Fill out the form and click "Calculate One Rep Max" to see your personalized strength metrics.
Understanding One Rep Max
What Is One Rep Max?
One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. It's a key metric for strength training that helps you:
Measure Strength
Your 1RM provides a baseline measurement of your current strength level, allowing you to track progress over time.
Program Workouts
Most strength programs prescribe weights as percentages of your 1RM, making it essential for proper training intensity.
Set Goals
Having a specific 1RM target gives you a clear, measurable goal to work toward in your strength training journey.
Why Calculate 1RM?
Directly testing your true 1RM can be risky and impractical to do frequently. Using a calculator allows you to:
- Safely Estimate: Calculate your 1RM without the risk of injury from maximal lifting
- Train Optimally: Determine appropriate weights for different rep ranges
- Track Progress: Monitor strength gains without maximal testing
- Plan Effectively: Design progressive overload into your training program
Learn How One Rep Max Is Calculated
Our calculator uses three established formulas to estimate your one-rep max with the highest possible accuracy:
Brzycki Formula
1RM = weight × (36 / (37 - reps))
Epley Formula
1RM = weight × (1 + (reps / 30))
Lander Formula
1RM = (100 × weight) / (101.3 - 2.67123 × reps)
We take the average of all three formulas to give you the most reliable estimate possible. This methodology provides a balanced result that compensates for the slight variations between different calculation methods.