One Rep Max Calculator
Calculate your maximum strength using 7 proven scientific formulas. Get personalized training zones and strength standards for men and women.
Your Lift Information
Your Results
Estimated One Rep Max
Results by Formula
Training Zones Based on Your 1RM
| Intensity | Weight | Reps | Zone |
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Your Strength Level
| Level | Ratio (to Body Weight) |
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💪 Welcome to the One Rep Max Calculator
Enter your lift information on the left and click “Calculate 1RM” to get your personalized results.
Understanding One Rep Max Training
What is One Rep Max?
Your One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition with proper form. It’s a key measure of your maximum strength and helps you plan effective training programs.
Why Calculate Your 1RM?
Testing your actual 1RM can be risky. This calculator estimates it safely using proven mathematical formulas based on submaximal lifts. It helps you plan training loads without risking injury from maximum attempts.
Training Zones Explained
Max Strength (95-100%): 1-2 reps. Strength (85-95%): 3-5 reps. Power/Hypertrophy (70-85%): 6-10 reps. Hypertrophy (60-70%): 8-15 reps. Endurance (45-60%): 15+ reps.
Formula Accuracy
Different formulas work better for different rep ranges. Epley works best for 1-10 reps. Brzycki is conservative and NCAA validated. Lombardi works better for higher reps. This calculator averages all 7 formulas for accuracy.
RPE Adjustment
Rate of Perceived Exertion (RPE) accounts for how hard your set felt. If you didn’t go to failure, RPE adjustment gives more accurate estimates. RPE 10 means maximum effort with no reps left in reserve.
Safe Testing Tips
- Always warm up thoroughly first
- Use proper form over maximum weight
- Have a spotter for safety
- Test when well-rested
- Use 2-10 reps for most accuracy
- Allow recovery between attempts
Important Safety Information
This calculator provides estimates based on scientific formulas. Your actual 1RM may vary based on training style, muscle fiber type, fatigue levels, and other factors. Always use proper form and have a spotter when testing heavy lifts. Consult with a qualified strength coach before attempting maximum lifts, especially for complex movements like squats and deadlifts.