Free tools
One rep max calculator.
Estimate your max from any set. Enter the weight and how many reps you got to failure.
How it works
Epley, with Brzycki beside it.
Both formulas turn a set taken to failure into an estimated single. load uses Epley for the estimated 1RM on your PRs, so this page leads with it.
Epley: 1RM = weight × (1 + reps ÷ 30)
Brzycki: 1RM = weight × 36 ÷ (37 − reps)
A single is its own 1RM, so 1 rep returns the weight you lifted. Example: 100 kg × 5 gives 116.7 kg (Epley) and 112.5 kg (Brzycki).Limits
- Most reliable from 2 to 10 reps. The further from a single, the looser the guess.
- Only for sets taken to failure, or very close to it.
- Accuracy differs by lift and by lifter. Neither formula is best for everyone (LeSuer et al. 1997).
- An estimate is not a tested max. Work up with a spotter if you test one.
Sources
- Epley B. Poundage Chart. Boyd Epley Workout, Lincoln, Nebraska, 1985.
- Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation and Dance 64(1):88 to 90, 1993.
- LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research 11(4):211 to 213, 1997.