How to Use the 1RM Calculator
Complete guide to calculating your one-rep max and understanding the results
🚀 Quick Start
Step 1: Enter Your Lift
- • Select your exercise (Bench Press, Squat, etc.)
- • Enter the weight you lifted
- • Choose your unit (lbs or kg)
Step 2: Add Repetitions
- • Enter how many reps you completed
- • Best accuracy with 1-10 reps
- • Maximum 15 reps supported
📊 Understanding the Formulas
Epley Formula (Recommended)
1RM = Weight × (1 + Reps/30)
Most widely used and accurate for most lifters. Great for 2-10 rep ranges.
Brzycki Formula
1RM = Weight × (36/(37-Reps))
More conservative estimate, works well for higher rep ranges (6-12 reps).
Lombardi Formula
1RM = Weight × (Reps^0.10)
Based on exponential relationship, good for experienced lifters.
O'Conner Formula
1RM = Weight × (1 + Reps/40)
More conservative than Epley, suitable for beginners.
🎯 Using Training Percentages
Strength Training
95-100% 1RM Testing
90-95% Max Strength
85-90% Heavy Singles
Volume Training
80-85% 3-5 Reps
70-80% 6-8 Reps
65-75% 8-12 Reps
⚠️ Safety Guidelines
Before Testing
- • Proper warm-up is essential
- • Have a qualified spotter
- • Use proper form at all times
- • Don't test when fatigued
Important Notes
- • Calculated 1RM is an estimate
- • Start conservatively in training
- • Listen to your body
- • Consider hiring a coach
💡 Tips for Better Accuracy
1
Use Your Best Recent Lift
Enter the heaviest weight you've lifted recently with good form.
2
Lower Rep Ranges Are More Accurate
1-6 reps give the most accurate 1RM estimates.
3
Compare Multiple Formulas
Use "Compare All Formulas" to see the range and pick what feels right.
4
Consider Your Experience Level
Beginners may find actual 1RM lower than calculated due to technique limitations.