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One-Rep Max Calculator
Calculate your one-rep max (1RM) for any lift. Your one-rep max is the max weight you can lift for a single repetition for a given exercise.
Example Inputs
Try these example values:
- Bench Press: 80kg for 8 reps
- Squat: 100kg for 5 reps
- Deadlift: 120kg for 3 reps
Your One-Rep Max Results
Enter your weight and reps above to calculate your one-rep max.
Estimated 1RM
Average from multiple formulas
Formula Breakdown
- Epley: 0 kg
- Brzycki: 0 kg
- Lombardi: 0 kg
Training Percentages
| Percentage | Weight | Reps |
|---|
Percentage of 1RM (100% to 50%)
| Percentage of 1RM | Lift Weight | Repetitions of 1RM |
|---|
Repetition Percentages of 1RM
| Repetitions | Lift Weight | Percentage of 1RM |
|---|
What This Means
Your estimated one-rep max is calculated using multiple formulas to provide a more accurate result. This is the maximum weight you could theoretically lift for one repetition with proper form.
The training percentages table shows recommended weights for different rep ranges based on your 1RM. These can be used to structure your training program.
Understanding One-Rep Max (1RM)
What is a One-Rep Max?
A one-rep max (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 used by athletes, powerlifters, and fitness enthusiasts to track progress and program training.
Testing your true 1RM can be risky, especially for beginners. That's why this calculator estimates your 1RM based on the weight you can lift for multiple repetitions, which is safer and still provides a reliable estimate.
How We Calculate Your 1RM
This calculator uses three well-established formulas to estimate your one-rep max:
- Epley Formula: 1RM = Weight × (1 + Reps/30)
- Brzycki Formula: 1RM = Weight × 36 / (37 - Reps)
- Lombardi Formula: 1RM = Weight × (Reps)0.1
We then take the average of these three formulas to provide a more accurate estimate. Different formulas may work better for different individuals and exercises, so the average helps account for these variations.
How to Use Your 1RM in Training
Your one-rep max is a valuable tool for programming your training. Here's how to use it:
- Strength Training: Use percentages of your 1RM to determine appropriate weights for different rep ranges. For example, 85% of 1RM is typically used for sets of 5 reps.
- Progress Tracking: Regularly recalculate your 1RM to track strength gains over time.
- Goal Setting: Set specific 1RM targets for your lifts as measurable goals.
The training percentages table in the results section provides specific weight recommendations based on your 1RM for different rep ranges.
Safety Considerations
While knowing your 1RM is useful, there are important safety considerations to keep in mind:
- Always use proper form, especially when lifting heavy weights.
- Have a spotter when attempting heavy lifts, particularly for exercises like the bench press and squat.
- Beginners should focus on developing proper technique before attempting maximal lifts.
- Listen to your body and avoid pushing through pain or discomfort.
- Gradually increase weights over time rather than making large jumps.
Remember that this calculator provides an estimate. Your actual 1RM may vary based on factors like technique, fatigue, and individual biomechanics.
Frequently Asked Questions
What is a one-rep max (1RM)?
A one-rep max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise with proper form. It's a standard measure of strength used in strength training and powerlifting.
How accurate is a 1RM calculator?
1RM calculators provide estimates that are generally accurate within 5-10% of your true max. The accuracy tends to decrease when using higher rep ranges (above 10 reps). For best results, use weights you can lift for 1-10 reps.
Is it safe to test my true 1RM?
Testing a true 1RM can be risky, especially for beginners. It requires proper technique, adequate warm-up, and often a spotter. It's safer to use a calculator to estimate your 1RM based on weights you can lift for multiple reps with good form.
Which formula is most accurate for calculating 1RM?
No single formula is universally most accurate for all individuals and exercises. That's why this calculator uses multiple formulas (Epley, Brzycki, and Lombardi) and provides an average. Different formulas may work better for different people and exercises.
How often should I recalculate my 1RM?
For tracking progress, recalculating your 1RM every 4-8 weeks is generally sufficient. More frequent testing can interfere with your regular training program and may not show significant changes.
Can I use this calculator for any exercise?
Yes, you can use this calculator for any resistance exercise where you can count repetitions. However, the accuracy may vary between different exercises. It tends to be most accurate for compound movements like squats, bench press, and deadlifts.