Weightlifting Rep Max Calculator
Calculate your one-rep max and optimal training weights for any exercise
Safety Warning: Maximal lifting requires proper technique and spotting. Never attempt 1RM testing without supervision if inexperienced. Consult a physician before beginning any strength training program.
Tip: For accurate results, use a weight you can lift for 2-10 reps with good form.
Your Recent Lift
Calculation Options
Strength Analysis
Estimated 1 Rep Max (1RM):
Estimated 3 Rep Max:
Estimated 5 Rep Max:
Estimated 10 Rep Max:
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Recommended Training Zones
| Goal | % of 1RM | Weight | Reps |
|---|---|---|---|
| Max Strength | 85-100% | - | 1-5 |
| Strength/Hypertrophy | 75-85% | - | 6-8 |
| Hypertrophy | 65-75% | - | 8-12 |
| Endurance | 55-65% | - | 12-15+ |
Training Notes:
- Always warm up properly before heavy lifts
- Increase weight gradually (2-5% weekly)
Understanding Rep Max Calculations
Popular 1RM Formulas
- Brzycki: 1RM = w × (36 / (37 - r)) - Most accurate for ≤10 reps
- Epley: 1RM = w × (1 + 0.0333 × r) - Favored by powerlifters
- Lander: 1RM = (100 × w) / (101.3 - 2.67123 × r) - Best for Olympic lifts
- O'Conner: 1RM = w × (1 + 0.025 × r) - Simple general formula
Training Zone Benefits
- Max Strength: Neural adaptations, improved recruitment
- Strength/Hypertrophy: Balance of size and strength gains
- Hypertrophy: Maximum muscle growth stimulation
- Endurance: Improved muscular stamina and conditioning
"Intermediate lifters using proper training zones gain strength 2.3x faster than those training at arbitrary intensities."
Exercise-Specific Considerations
Compound Lifts
Squat, bench press, and deadlift typically allow higher 1RM percentages than isolation exercises. Form breakdown occurs more suddenly at maximal weights - always use safeties or spotters.
Olympic Lifts
The explosive nature of cleans and snatches means technique fails before absolute strength. 1RM testing should only be done with perfect form - consider 3RM tests instead for safer estimation.
Isolation Exercises
Most isolation moves (curls, extensions) aren't suited for true 1RM testing. Use 5-10RM ranges for estimation and focus on time-under-tension for growth.
Pro Tip: Your 1RM can vary by 5-10% daily based on recovery, nutrition, and stress. Test under consistent conditions for accurate tracking.
Frequently Asked Questions
How often should I test my 1RM?
Most lifters benefit from testing true 1RM only 2-4 times per year. Intermediate lifters can estimate from rep maxes monthly. Beginners should focus on technique before max testing.
Why do different formulas give different results?
Each formula accounts for fatigue differently. Brzycki is most accurate for ≤10 reps while Epley works better for powerlifters. Differences are typically 2-5% between formulas.
Should I use the same percentages for all exercises?
No. Compound lifts typically use higher percentages than isolation moves. For example, bicep curls might use 5-10% lower percentages than the calculator suggests for optimal stimulus.
How does training age affect 1RM calculations?
Advanced lifters can typically perform more reps at higher percentages of their 1RM than beginners. Our calculator adjusts for experience level in its estimations.
Can I use this for bodyweight exercises?
Rep max calculations work poorly for most bodyweight exercises due to technique variables. For pull-ups/push-ups, use rep maxes directly rather than estimating 1RM.