One Rep Max Calculator
Calculate your 1RM (one rep max) for weightlifting. Get training percentages for different rep ranges and strength standards comparison.Inputs
Used for strength standard comparison
Include the bar weight (usually 45 lbs)
1-10 reps most accurate, 10+ less reliable
Used for relative strength comparison
Enter values to see results
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What is this?
A One Rep Max (1RM) calculator estimates the maximum weight you can lift for one repetition based on submaximal effort. It's used for programming training intensity, tracking progress, and comparing strength levels without the risk of testing true 1RM.How to use
Choose your preferred unit system (Imperial or Metric). Select your exercise, enter the weight you lifted and how many clean reps you completed. The calculator estimates your 1RM using multiple formulas and provides training percentages for different goals. For best accuracy, use 3-8 rep range.Tips
- Most accurate with 3-8 reps - 1-2 reps is your actual max, 10+ reps becomes less reliable
- Only count clean reps - form breakdown means stop counting
- Warm up properly before testing - cold muscles increase injury risk
- Use lifting straps/belt for deadlift if you normally use them - test in competition conditions
- Beginner (<1 year): Train 70-80% 1RM, Intermediate (1-3 years): 75-85%, Advanced (3+ years): 80-95%
- Retest 1RM every 8-12 weeks to track progress and adjust training loads
- Strength standards: Bench 1.5x bodyweight = intermediate, 2x = advanced (applies to both lbs and kg ratios)
- Don't test true 1RM frequently - high injury risk, use calculator instead
- Olympic barbells: Standard = 45 lbs (20 kg), Women's = 35 lbs (15 kg)
Disclaimer: This calculator provides estimates for informational purposes only and does not constitute medical advice. Results are based on general formulas and may not account for individual health conditions. Consult a qualified healthcare professional for personalized guidance. See our full disclaimer for details.