1RM Calculator
Calculate Your
One Rep Max
Estimate your one-rep max (1RM) based on the weight and reps you can lift. Your 1RM is the maximum weight you can lift for a single repetition. This calculator uses proven formulas to help you plan your training intensity.
Enter the weight you lifted and how many reps you completed. For best accuracy, use a weight you can lift for 2-10 reps.
This calculator provides estimates based on mathematical formulas. Actual 1RM may vary based on factors like technique, fatigue, and training experience. Always use a spotter when attempting heavy lifts and consult a qualified trainer if you're new to strength training.
Training Percentages
Weight by Intensity
Use these percentages to plan your training. Lower percentages with higher reps build muscle endurance and size, while higher percentages with lower reps build maximal strength.
| % | Weight | Use Case | Rep Range |
|---|---|---|---|
How to Use This
Quick Guide
How to Use the 1RM Calculator
Follow these steps to estimate your one-rep max:
Select Units
Choose kg or lb for your weight
Enter Weight
Input the weight you lifted during your set
Enter Reps
Input reps completed (2-10 reps for best accuracy)
Choose Formula
Select a formula - Epley works for most
Calculate
Get your estimated 1RM and training percentages
About 1RM
Understanding One Rep Max
What is 1RM?
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's a key metric for measuring strength progress and programming training intensity.
Why Estimate Instead of Test?
Testing true 1RM can be fatiguing and risky, especially without a spotter. Estimation allows you to track progress and program training without the recovery cost of maximal lifts.
Which Formula is Best?
The Epley formula works well for most people. Brzycki is often more accurate for low-rep sets (under 10). The accuracy of any formula decreases as rep count increases beyond 10.
Tips for Accuracy
Use a weight you can lift for 3-8 reps to failure or near-failure. Higher rep estimates (10+) tend to be less accurate. Test with good form on compound lifts like bench, squat, or deadlift.
Built for progress
Take the guesswork out of training
Create personalized AI-powered workout plans that evolve with you. Train smarter, track every rep and keep moving forward, one workout at a time.
