Epley Formula Calculator
Calculate your 1RM using the proven Epley equation for safe strength training
What is Epley for 1RM
1RM stands for “one rep maximum” – the heaviest weight you can lift for one full repetition.
Instead of testing this directly (which can be risky), the Epley formula helps you estimate it safely using lighter weights for multiple reps.
This gives you the same training information while keeping you safe.
How the Epley Formula Works
The formula is straightforward:
200 × (1 + 8 ÷ 30) = 240 pounds
The formula works well for 2-12 repetitions and provides reliable estimates.
Why Use This Calculator Instead of Testing Your Max?
Testing your true 1RM means lifting extremely heavy weights, which can strain your muscles or cause injury.
The calculator provides the same workout planning information without the risk.
You can track your progress safely and adjust your training regularly.
How to Use Your 1RM for Better Training
Once you have your estimated 1RM, use these percentages to plan your workouts:
- 60-75%: Building endurance and learning proper form
- 75-85%: Building overall strength
- 85-95%: Developing power and speed
For example, if your 1RM is 200 pounds, use 150-170 pounds for strength building.
Epley vs Other Strength Prediction Methods
How Epley Compares to Other Formulas
There are several ways to predict your 1RM. Epley works well for most people doing 2-10 repetitions. Other formulas like Brzycki work better for higher reps (6-12), while McGlothin is good for endurance training (10+ reps). The calculator shows you comparisons so you can see different estimates.
Why Formulas Aren’t Perfect
No formula gives exact results because everyone is different. Your genetics, how long you’ve been training, and recovery all affect your actual strength. The Epley formula is usually within 5-10% of your true maximum. Use it as a guide, not an absolute rule, and retest every few months to track progress.
Training with Percentages
Training Weight Ranges
- 60-75% of 1RM: Lighter weights for building endurance (8-15 reps)
- 75-85% of 1RM: Moderate weights for building strength (4-8 reps)
- 85-95% of 1RM: Heavy weights for power and maximal strength (1-4 reps)
Your training weight depends on your goals. For general strength, use 75-85% of your 1RM. Rest 2-3 minutes between sets for heavy weights, 60-90 seconds for lighter weights.
⚕️ Important Safety Information
This Epley calculator provides strength predictions based on scientifically validated formulas. Results are estimates and may vary based on individual factors. Always prioritize safety and consult healthcare professionals before starting new training programs. Never attempt weights that compromise your form. The calculations provided are for educational purposes and general guidance only.