One Rep Max (1RM) Calculator

Scientific Strength Calculator for Bench Press, Squats & Deadlifts

Free 1RM calculator to predict your one-rep max for any exercise. Get accurate estimates for bench press, squats, deadlifts and more without the risk of actual maximum testing.

1RM Calculator

Estimate your one-rep maximum with proven formulas. Also calculate Rep Max and Percentages of 1RM.

Results

Example 1RM Results using different formulas:

  • MultiModal Formula: 100kg bench press for 5 reps = 113.6kg 1RM
  • Brzycki Formula: 100kg squat for 5 reps = 114.5kg 1RM
  • Epley Formula: 100kg deadlift for 5 reps = 116.7kg 1RM

Rep Max

Example Rep Max calculations for 100kg 1RM:

  • 3RM (3 Rep Max): 95kg
  • 5RM (5 Rep Max): 87kg
  • 10RM (10 Rep Max): 75kg

Percentages of 1RM

Example percentages of 100kg 1RM:

  • 90% of 1RM: 90kg - Typically used for heavy singles and doubles
  • 80% of 1RM: 80kg - Common working weight for strength training
  • 70% of 1RM: 70kg - Often used for higher rep training

How to Use the 1RM Calculator

  1. 1Enter the weight you can lift for multiple reps
  2. 2Enter the number of reps you can perform with that weight (3-20)
  3. 3Click "Calculate" to get your estimated one rep max
  4. 4View detailed results including rep max ranges and training percentages

Note: For best accuracy, use a weight you can lift with proper form for 3-10 reps. Our calculator works for all major lifts including Bench Press, Squat, Deadlift, and more.

Popular Exercises

Calculate 1RM for any strength training exercise

Bench Press 1RM

Essential upper body compound movement for chest, shoulders and triceps strength development

Squat 1RM

Fundamental lower body exercise for overall strength and muscle development

Deadlift 1RM

Full body compound movement for maximum strength gains

Why Choose Our Calculator

Multiple Scientific Formulas

Using proven formulas like Epley and Brzycki to provide accurate one rep max predictions

Safe & Scientific Testing

Predict your 1RM safely without the risks of actual maximum testing

Comprehensive Results

Get detailed percentages and training recommendations based on your one rep max

Frequently Asked Questions

What is 1RM?

1RM (One Rep Maximum) is the maximum weight you can lift for a single repetition of an exercise with proper form. It's a key indicator of your strength level.

How accurate are the calculations?

Our calculator uses multiple scientifically validated formulas, including Epley and Brzycki, providing accuracy typically within 5-10% of your actual 1RM. Based on extensive research and real-world testing data, it provides reliable estimates for your true 1RM.

Does it work for both men and women?

Yes, absolutely! The formulas are scientifically proven to be equally accurate for both men and women. Gender does not affect the accuracy of the calculations.

Is it safe to test my actual 1RM?

Testing your actual 1RM can be risky, especially without proper experience or supervision. This calculator provides a safe way to estimate your 1RM without the risks of maximal lifting.

Which exercises can I use this calculator for?

The calculator works for any strength exercise, but it's most commonly used for compound movements like Bench Press, Squat, Deadlift, as well as isolation exercises like Bicep Curls.

How often should I recalculate my 1RM?

It's recommended to recalculate your 1RM every 4-6 weeks to track progress, or whenever you feel significant strength gains.