One-Rep Max Formula Comparison Calculator
Compare Epley, Brzycki and Lombardi 1RM estimates.
Enter your values
ⓘ Live results
Results
- Epley
- 116.7 kg
- Brzycki
- 112.5 kg
- Lombardi
- 117.5 kg
- Average
- 115.5 kg
Quick answer
1RM estimation formulas typically agree within a few kg for rep ranges under about 10.
Epley: 1RM = w(1+r/30); Brzycki: 1RM = w x 36/(37-r); Lombardi: 1RM = w x r^0.10
How to use the One-Rep Max Formula Comparison Calculator
- 1Enter the weight lifted and reps completed to failure or near failure.
- 2Formulas are most accurate for sets of 10 reps or fewer; higher reps reduce accuracy.
- 3Never attempt an actual 1RM test without a spotter and proper warm-up.
Worked example
Using the values the calculator loads with:
Inputs
- Weight lifted100 kg
- Reps completed5
Results
- Epley116.7 kg
- Brzycki112.5 kg
- Lombardi117.5 kg
- Average115.5 kg
Frequently asked questions
Which formula is most accurate?
None is universally best; Brzycki tends to underestimate at higher rep counts, Epley slightly overestimates.
Can I use this for programming?
Yes — estimated 1RM is commonly used to set percentage-based training loads.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.