One Rep Max Calculator
Estimate your one-repetition maximum (1RM) for weightlifting exercises to optimize your training program and track strength progress.
Your One-Rep Max Results
Estimated 1RM
120 kg
(Brzycki formula)
Strength Level
Intermediate
Training Recommendations
Based on your estimated 1RM, focus on progressive overload with 3-5 sets of 3-6 reps at 80-85% of your 1RM for strength development.
Training Weight Percentages
| % of 1RM | Weight | Rep Range | Training Goal |
|---|---|---|---|
| 90-100% | 108-120 kg | 1-3 | Maximal strength |
| 80-89% | 96-107 kg | 4-6 | Strength |
| 70-79% | 84-95 kg | 8-12 | Hypertrophy |
| 60-69% | 72-83 kg | 12-15+ | Endurance |
One-Rep Max (1RM)
Your one-repetition maximum (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. Knowing your 1RM helps you design effective strength training programs by allowing you to train at specific percentages of your maximum.
How to Calculate One-Rep Max
While the most accurate way to determine your 1RM is to actually perform a one-rep max test, this calculator estimates your 1RM based on the weight you can lift for multiple repetitions. Several formulas exist for this estimation:
Brzycki Formula (Most Common)
1RM = weight × (36 / (37 - reps))
Epley Formula
1RM = weight × (1 + 0.0333 × reps)
Lander Formula
1RM = (100 × weight) / (101.3 - 2.67123 × reps)
Strength Standards
| Level | Male (kg) | Female (kg) | Description |
|---|---|---|---|
| Untrained | Below 50 | Below 30 | No prior training experience |
| Novice | 50-80 | 30-50 | 3-9 months of training |
| Intermediate | 80-110 | 50-75 | 1-2 years of training |
| Advanced | 110-140 | 75-95 | 3-5 years of training |
| Elite | 140+ | 95+ | Competitive level |
* Standards are for bench press and may vary by exercise
Training Tip:
For most lifters, testing your true 1RM more than once every 3-6 months isn't necessary. Instead, use estimated 1RM from submaximal loads (3-8 reps) to track progress while reducing injury risk.
Frequently Asked Questions
What is a one-rep max (1RM)?
A one-repetition maximum (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise with proper form. It's a common measure of strength in weight training and is used to determine training loads for different goals.
How accurate are 1RM calculators?
1RM calculators provide estimates that are generally within 5-10% of your actual 1RM for most people. Accuracy decreases as the number of reps used for estimation increases (best with 3-8 reps). Different formulas may give slightly different results, which is why we provide multiple options.
How often should I test my 1RM?
For most lifters, testing your true 1RM more than once every 3-6 months isn't necessary and increases injury risk. Instead, use estimated 1RM from submaximal loads (3-8 reps) to track progress. Competitive powerlifters may test more frequently before competitions.
Why do different formulas give different results?
Different formulas were developed from different datasets and populations. Some may be more accurate for certain rep ranges or exercises. Brzycki is generally most accurate for lower reps (1-5), while Epley may work better for higher reps (5-10). The differences are usually small (±5%) for most lifters.
Can I use this for all exercises?
Yes, but accuracy may vary. These formulas work best for compound lifts like bench press, squat, and deadlift. They may be less accurate for isolation exercises or those with different strength curves. The strength standards provided are primarily for bench press - other lifts have different standards.