One rep max calculator
Enter a weight you lifted and the number of reps you completed. This 1RM calculator estimates the heaviest load you could move for a single rep, using the Epley formula, and prints training percentages of that number.
Estimated one rep max
116.7 kg
Epley estimate from 100 kg for 5 reps.
| Percent | Load (kg) | Reps at this load |
|---|---|---|
| 100% | 1 rep | |
| 95% | 2 reps | |
| 90% | 4 reps | |
| 85% | 5 reps | |
| 80% | 8 reps | |
| 75% | 10 reps | |
| 70% | 12 reps | |
| 65% | 15 reps |
What the percentages are for
The 70 to 85% band covers most working sets. Lower percentages carry more reps, higher percentages fewer.
A program does not print a weight, because the right load changes with the week, the lift and the day. Each working set carries an effort target written as reps in reserve, and you pick the load that lands on it.
Using this as a max bench calculator
The formula reads a weight and a rep count, so the same arithmetic covers bench press, squat, deadlift and overhead press. The formula is more accurate on some lifts than others. Bench press and overhead press tend to estimate close, because the set ends when the bar stops moving. Squat and deadlift sets in the 10 to 15 rep range tend to read high, since those sets often end on breathing or grip rather than on the muscle that was being loaded.
Epley is one formula of several
This page uses Epley: 1RM = weight x (1 + reps / 30). Brzycki, Lombardi and Wathan are other common ones, and they return different numbers from the same set. All of them estimate from a formula.
The estimate loses accuracy the further the rep count sits from 1. A set of 3 to 5 reps taken close to failure produces the tightest figure. At 12 to 15 reps the answer depends on conditioning and pain tolerance as much as on strength, which is why the calculator stops at 15.
Programs with effort targets printed on every working set.
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