One Rep Max (1RM) Calculator
Calculate your One Rep Max (1RM) with our free strength calculator. Using the Epley, Brzycki, and Lombardi formulas, this tool estimates the maximum weight you can lift for one repetition based on your submaximal performance. Perfect for strength training, powerlifting, and program design.
How to Use This Tool
1. Enter Weight
kg or lbs
2. Enter Reps
1-10 repetitions
3. Choose Formula
Epley, Brzycki, or Lombardi
4. Set Date
Track your progress
5. Get Results
View 1RM & training loads
Formula & Calculation
Results are rounded to 1 decimal place for clarity.
Quick Reference 1RM Table
| Weight (kg) | 3 reps | 5 reps | 8 reps | 10 reps |
|---|---|---|---|---|
| 50 | 55.0 | 58.3 | 63.3 | 66.7 |
| 60 | 66.0 | 70.0 | 76.0 | 80.0 |
| 70 | 77.0 | 81.7 | 88.7 | 93.3 |
| 80 | 88.0 | 93.3 | 101.3 | 106.7 |
| 90 | 99.0 | 105.0 | 114.0 | 120.0 |
| 100 | 110.0 | 116.7 | 126.7 | 133.3 |
How We Calculated
- Input: We collected your lifted weight, repetitions, and selected formula.
- Conversion: Weight is converted to kg if entered in lbs.
- Formula: Applied the selected formula (Epley, Brzycki, or Lombardi).
- Training Percentages: Calculated 50% to 95% of your 1RM for training planning.
Why Trust This Tool?
Epley, Brzycki, Lombardi
No server storage
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Works on all devices
Latest strength science
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Accuracy & Standards
This calculator uses three validated 1RM estimation formulas: Epley (simple, widely used), Brzycki (often considered most accurate), and Lombardi (better for higher reps). Results are rounded to 1 decimal place. The tool is for educational and training purposes—not a substitute for professional strength coaching.
Unit Relationship
1 kg = 2.20462 lbs
1 lb = 0.453592 kg
Learn About One Rep Max
What is 1RM?
One Rep Max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's a fundamental metric for strength training, powerlifting, and program design.
Why Test 1RM?
Knowing your 1RM allows you to program training loads accurately, track strength progress, and periodize your workouts. It's essential for strength athletes and anyone serious about training.
Submaximal Testing
Estimating 1RM from submaximal lifts (3-10 reps) is safer than attempting a true 1RM, especially for beginners. These formulas provide reliable estimates for training purposes.
Real-World Examples
- Example 1: Bench press 80 kg for 5 reps → Epley: 93.3 kg, Brzycki: 90.0 kg, Lombardi: 92.4 kg
- Example 2: Squat 100 kg for 3 reps → Epley: 110.0 kg, Brzycki: 105.9 kg, Lombardi: 110.2 kg
- Example 3: Deadlift 140 kg for 8 reps → Epley: 177.3 kg, Brzycki: 170.6 kg, Lombardi: 175.4 kg
Limitations of This Tool
- Provides estimates—individual variation exists (±5-10%).
- Assumes proper lifting form and consistent technique.
- Does not account for fatigue, recovery, or exercise-specific factors.
- For safety, always use a spotter and warm up properly before attempting heavy lifts.
Trust & Privacy
We take your privacy seriously. This tool:
- Does not store data on any server
- All calculations happen locally in your browser
- No cookies are used for this tool
References
- Epley B. Poundage chart. In: Boyd Epley, Strength and Conditioning. 1985.
- Brzycki M. A practical approach to strength training. 1998.
- Lombardi VP. Weight training glossary. 1989.
- National Strength and Conditioning Association. Essentials of Strength Training and Conditioning.
Editorial Process
The Healthtus editorial team, consisting of certified strength coaches and fitness experts, reviews this tool regularly to ensure accuracy and alignment with the latest strength science. We update the content and references as new research emerges.
Last reviewed: July 2026