One-rep max calculator
Enter a weight and the reps done with it. You get an estimated one-rep max and the load range for each training adaptation.
Estimated one-rep maxEstimated
218
Epley 222, Brzycki 215, in the units you entered
| Training adaptation | % 1RM | Load |
|---|---|---|
| Power (with weights) | 30-45% | 65-98 |
| Stabilization and muscular endurance | 50-70% | 109-153 |
| Muscular hypertrophy | 75-85% | 164-185 |
| Maximal strength | 85-100% | 185-218 |
Then plan the phase
Loads, sets, reps, tempo and rest for each training phase are among the most tested facts in Program Design, 20% of the exam.
Questions people ask
How do you estimate a one-rep max?
From a set of 10 reps or fewer taken close to failure. Epley multiplies the weight by 1 plus reps divided by 30; Brzycki multiplies it by 36 divided by (37 minus reps). This calculator shows both and uses their average.
What percentage of 1RM is used for each training goal?
NASM's study guide suggests about 50-70% of 1RM for stabilization and muscular endurance, 75-85% for hypertrophy, 85-100% for maximal strength, and about 30-45% for power with weights.
Why only up to 10 reps?
Estimates from longer sets drift further from a true maximum, so the calculator accepts 1 to 10 reps.
Is a tested one-rep max safe for every client?
A true one-rep max test suits trained clients. For newer clients, an estimate from a lighter set is the safer choice.