Calculators
45-degree leg press one-rep max calculator
Enter the weight and reps of a recent set of the 45-degree leg press. 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
45-degree leg press
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.
On the leg press, people fit more reps at each percentage than on the bench press, so you may beat the rep estimates in the table.
How to do it
45-degree leg press
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 back squat
One-rep max
Barbell Romanian deadlift
One-rep max
Barbell deadlift
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.