One-Repetition Maximum (1RM) Estimator
Estimate your one-rep max (1RM) from a submaximal set with the Epley, Brzycki and Lombardi formulas, plus a percentage table.
Your inputs
Results
Estimated 1RM (average of formulas)
115.5
- Epley
- 116.7
- Brzycki
- 112.5
- Lombardi
- 117.5
≈Estimate based on the stated model and assumptions
Notes for this result
- Estimates are most accurate from sets of about 10 reps or fewer. Test true maximums only with proper technique and a spotter.
| % of 1RM | Load |
|---|---|
| 100% | 115.5 |
| 95% | 109.8 |
| 90% | 104 |
| 85% | 98.2 |
| 80% | 92.4 |
| 75% | 86.7 |
| 70% | 80.9 |
| 65% | 75.1 |
| 60% | 69.3 |
Inputs are never added to links for financial, salary or health calculators.
What this calculator does
Testing a true one-rep max is demanding. Estimating it from a set of several reps is safer and good enough for programming.
Formula and method
Worked example
Calculated by this tool with its default inputs:
Inputs
- Weight lifted: 100 kg or lb
- Repetitions completed: 5
Results
- Estimated 1RM (average of formulas): 115.5
- Epley: 116.7
- Brzycki: 112.5
- Lombardi: 117.5
How to read the results
Use the percentage table to choose training loads.
Assumptions and limitations
- Most accurate for sets of about 10 reps or fewer.
- Use proper technique and a spotter for heavy lifts.
Health results are general estimates for adults and do not replace medical advice, diagnosis or treatment. Speak to a qualified health professional about your personal situation, especially during pregnancy or if you have a medical condition.
Questions
Why do the formulas differ?
They were fitted to different populations and rep ranges; averaging smooths the differences.
Methodology and verification
- Result type
- Estimate based on the stated model and assumptions
- Formula version
- 1.0
- Automated verification
- 3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Because this calculator can involve personal financial or health details, your inputs are never added to share links or saved to history. Privacy policy