Calculators
Barbell back squat one-rep max calculator
Enter the weight and reps of a recent set of the barbell back squat. With 100 lb for 8 reps, the Epley formula estimates a one-rep max of 126.7 lb.
One-rep max
Loads by percentage of your max
| % of max | Weight | Reps, estimated |
|---|---|---|
| 100% | 126.7 lb | 1 |
| 95% | 120 lb | 2 |
| 90% | 114 lb | 3 |
| 85% | 108 lb | 5 |
| 80% | 101 lb | 8 |
| 75% | 95 lb | 10 |
| 70% | 89 lb | 13 |
| 65% | 82 lb | 16 |
| 60% | 76 lb | 20 |
Which weight to use to build muscle
2 to 4 sets · 6 to 12 reps85 to 103 lb
To build muscle, the guide for this exercise uses 2 to 4 sets of 6 to 12 reps, ending each set with 1 to 3 reps in reserve. By the Epley formula, that is about 67% to 81% of your estimated max: with a max of 126.7 lb, about 85 to 103 lb per set.
The formula, step by step
Say your last good set was 100 lb for 8 reps.
Epley
max = weight × (1 + reps ÷ 30)
100 × (1 + 8 ÷ 30) = 100 × 1.27 = 126.7 lb
Brzycki
max = weight × 36 ÷ (37 − reps)
100 × 36 ÷ (37 − 8) = 3,600 ÷ 29 = 124.1 lb
Barbell back squat
For max strength, the guide for this exercise suggests 3 to 5 sets of 3 to 6 reps with 2 to 3 reps in reserve, once your form is solid.
How to do it
Barbell back squat
How it works
Both formulas turn a set done to fatigue into an estimate of the most you could lift once. They match at 10 reps; below 10, Epley comes out a little higher.
Use a recent set done with good form, and enter the reps you could have done: if you stopped after 8 with 2 more in the tank, enter 10. You do not need to test a true max.
Treat the result as an estimate. How many reps fit at a given percentage changes from person to person and from one exercise to another: in a meta-regression of 269 studies, people did more reps on the leg press than on the bench press at every load.
New to lifting? You do not need a one-rep max to start: the app finds your starting weights from the reps you have left in reserve.
One-rep max by exercise
Barbell hip thrust
One-rep max
Barbell Romanian deadlift
One-rep max
Barbell deadlift
One-rep max
45-degree leg press
One-rep max
Smith machine squat
One-rep max
Sources
Epley
Epley B. Poundage chart. In: Boyd Epley Workout. Lincoln (NE): Body Enterprises; 1985. p. 86.
Brzycki
Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. J Phys Educ Recreat Dance. 1993;64(1):88-90.
Reps, estimated
Nuzzo JL, Pinto MD, et al. Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise. Sports Med. 2024;54(2):303-321.
Watch your max go up
Log your sets in the app and see your estimated max for each exercise, week after week.