Knowing your One Rep Max (1RM) is essential for strength training programming, but testing it can be dangerous. Our calculator safely estimates your max based on your sub-maximal performance using the industry-standard Epley, Brzycki, McGlothin, and Lombardi formulas.
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One Rep Max Calculator
Calculate your one-rep max (1RM) using multiple proven formulas (Epley, Brzycki, etc.) based on your lift performance.
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Lift Details
About Formulas
Epley: Best for high reps (6+).
Brzycki: Standard for < 10 reps.
We use an average of 4 formulas for accuracy.
Note: 1RM calculations are estimates. Actual performance may vary.
Your One Rep Max
Estimated 1RM
115 lbs
Range: 113 - 117 lbs
Training Percentages
100%115 lbs
95%109 lbs
90%104 lbs
85%98 lbs
80%92 lbs
75%86 lbs
70%81 lbs
60%69 lbs
50%58 lbs
Formula Breakdown
Epley117 lbs
Brzycki113 lbs
McGlothin114 lbs
Lombardi117 lbs
About Calculate Your One Rep Max (1RM)
1
Lift Weight
Enter the weight you lifted for a specific exercise.
2
Repetitions
Enter the number of clean repetitions you performed (ideally between 3 and 10).
3
Review
See your estimated max and percentage breakdowns instantly.
Key Features
Multi-Formula Accuracy
Averages results from 4 different scientific formulas for the most reliable estimate.
Training Percentages
Instantly generates a table of your 50% to 100% lifting zones for programming.
Safe & Effective
Plan your heavy lifts without the risk of failing a true 1RM test.
Frequently Asked Questions
The Epley formula is generally best for higher reps (6+), while Brzycki is often cited as more accurate for lower reps (<5).
It is an estimate. Actual performance depends on daily fatigue, technique, and experience.
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