Using the One Rep Max Calculator
Use the same weight unit throughout: entering kilograms produces a kilogram estimate, and pounds produce a pound estimate. The supported range is one to twelve repetitions. Record the lift, technique and equipment separately when comparing sessions, since the calculator does not distinguish them.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Weight lifted (kg or lb)
- 60
- Repetitions
- 8
Example result
- Epley estimated 1RM
- 76
- Brzycki estimated 1RM
- 74.482759
Method and assumptions
Epley and Brzycki formulas; best suited to low-repetition sets. Estimates are not an instruction to attempt a maximal lift.
Compare like-for-like sessions
Training estimates are more useful when the recorded activity is consistent. Keep the same exercise, measurement method and definition of duration when comparing sessions. Equipment, conditions and effort can change the meaning of similar-looking numbers. A calculator can summarize the entries, but it cannot assess technique, recovery or whether a session is appropriate for you.
Common question
Why do the Epley and Brzycki estimates disagree?
They use different relationships between repetitions and load. Agreement is not guaranteed, particularly as repetitions increase. The difference is a reminder that both values are predictions from a set, rather than a direct test of maximum strength.
Guide updated .