One Rep Max Calculator
Estimate your maximum single-rep lift from submaximal data.
Fitness
Enter between 1 and 36 reps
Estimated 1RM (Average)
213.7 lbs
Epley
215.8
Brzycki
208.1
Lander
210.4
Lombardi
217.3
Mayhew
220.2
O'Conner
208.1
Wathan
215.7
Training Load Chart
100%
213.7 lbs
95%
203.0 lbs
90%
192.3 lbs
85%
181.6 lbs
80%
170.9 lbs
75%
160.2 lbs
70%
149.6 lbs
65%
138.9 lbs
60%
128.2 lbs
The Comprehensive Guide to One Rep Max (1RM) Calculator
What is a One Rep Max (1RM) Calculator?
The One Rep Max Calculator estimates the heaviest weight you could lift for a single repetition based on your performance at lighter loads. It uses seven scientifically validated formulas and averages them for reliability.
The Mathematical Formula
One Rep Max Analysis Model
This tool utilize standardized mathematical formulas and logic to calculate precise One Rep Max results.
Calculation Example
If you bench press 185 lbs for 5 reps:
- Epley estimated 1RM: ~215.8 lbs
- Brzycki estimated 1RM: ~208.1 lbs
- Average across all formulas: ~211.4 lbs
Strategic Use Cases
- Strength Programming: Set training loads based on percentages of your 1RM for progressive overload.
- Progress Tracking: Monitor estimated strength gains over time without maxing out.
Frequently Asked Questions
How accurate is this calculator?
Our calculator uses industry-standard formulas to provide the most accurate results possible. However, it should be used for informational purposes only.
Is this tool free to use?
Yes, all our calculators are 100% free to use. We do not require any registration, personal information, or subscriptions.