1RM Testing Protocols and the Formulas Behind Them

How to safely estimate your one-rep max using the Brzycki or Epley equations.

The Gold Standard of Strength

Your One-Rep Max (1RM) is the maximum weight you can lift for a single repetition with perfect form. It is the baseline for most strength training programs, used to calculate "percentages" for your daily workouts.

Estimation vs. True Max Testing

Performing a true 1RM test is taxing on the central nervous system and carries a higher risk of injury. For most trainees, estimating your 1RM from submaximal repetitions (e.g., how many times you can lift a weight for 5 reps) is safer and nearly as accurate.

The Epley Formula

1RM = Weight * (1 + 0.0333 * Reps)
Example: If you can lift 225lbs for 5 reps:
225 * (1 + 0.1665) = 262.5 lbs.

Which Formula is Best?

The Epley formula is popular for its simplicity, while the Brzycki formula is often cited as more accurate for rep ranges between 2 and 10. For most people, the results will be within 1-2% of each other.

Conclusion

Test, don't guess. Use our 1-Rep Max calculator to find your strength baseline and set your training percentages for your next block.

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