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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Calculate Your One Rep Max (1RM)
Estimate your one-rep max for any lift using 4 proven formulas (Epley, Brzycki, etc.). Calculate training percentages instantly. Fast, free, and private.
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About Calculate Your One Rep Max (1RM)
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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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