One-Rep Max Formula Comparison Calculator
Compare Epley, Brzycki and Lombardi 1RM estimates.
Enter your values
Enter the weight lifted in kg.
Enter the reps completed you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- 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
At a glance
| What it does | Compare Epley, Brzycki and Lombardi 1RM estimates. |
|---|---|
| Category | Fitness |
| Inputs needed | Weight lifted, Reps completed |
| Main output | Epley |
| Formula | Epley: 1RM = w(1+r/30); Brzycki: 1RM = w x 36/(37-r); Lombardi: 1RM = w x r^0.10 |
| Cost | Free — no sign-up, no download |
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.
Inputs explained
- Weight lifted(kg)
- Enter the weight lifted in kg.
- Reps completed
- Enter the reps completed you are working with.
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.
What do I need to enter into the One-Rep Max Formula Comparison Calculator?
Just 2 values: weight lifted, reps completed. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the One-Rep Max Formula Comparison Calculator work out the answer?
1RM estimation formulas typically agree within a few kg for rep ranges under about 10. It applies the formula Epley: 1RM = w(1+r/30); Brzycki: 1RM = w x 36/(37-r); Lombardi: 1RM = w x r^0.10 and shows the working so you can check each step by hand.
Is the One-Rep Max Formula Comparison Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.