Calculate your leg press 1RM (one-rep max) from the weight and reps you lifted, or find a working weight or rep count from your max, in lb or kg.
Leg Press Max Formula
The calculator uses the Epley one-rep max estimate. It estimates your leg press max from the weight you lifted and the number of repetitions you completed.
- 1RM = estimated one-rep max
- W = weight lifted
- R = repetitions performed
If you enter weight lifted and repetitions, the calculator solves for estimated max:
If you enter estimated max and repetitions, the calculator solves for the weight lifted:
If you enter weight lifted and estimated max, the calculator solves for repetitions:
The load fields use lb, kg, g or N. Newtons are converted using standard gravity, 9.80665 m/s²; this force equivalent does not account for sled angle or machine leverage. Select the quantity to find and enter the other two values.
Leg Press Max Reference Tables
Rep max estimates become less precise as reps get higher. Lower-rep sets usually give a better estimate of true maximum strength.
| Reps Performed | Multiplier Used | Estimated Max From 500 lb |
|---|---|---|
| 1 | 1.033 | 516.67 lb |
| 3 | 1.100 | 550.00 lb |
| 5 | 1.167 | 583.33 lb |
| 8 | 1.267 | 633.33 lb |
| 10 | 1.333 | 666.67 lb |
| Unit | Meaning | Approximate Conversion |
|---|---|---|
| lb | Pounds | 1 lb = 0.453592 kg |
| kg | Kilograms | 1 kg = 2.20462 lb |
| g | Grams | 1000 g = 1 kg |
| N | Newtons | 1 kg-force ≈ 9.80665 N |
Examples
Example 1: Estimate leg press max
You leg press 500 lb for 8 reps.
Your estimated leg press max is 633.33 lb.
Example 2: Find the working weight
Your estimated max is 600 lb, and you want to know what weight matches 5 reps.
The estimated 5-rep weight is 514.29 lb.
FAQ
Is a leg press max the same as a squat max?
No. A leg press max is usually much higher than a squat max because the machine supports your body and guides the path of movement. Do not use a leg press max to estimate a barbell squat max directly.
How accurate is the leg press max estimate?
It is an estimate, not a guaranteed true max. It is usually more useful when your rep count is low, such as 3 to 8 reps. Very high-rep sets can make the estimate less reliable because endurance becomes a bigger factor.
Should you test a true one-rep max on the leg press?
You can, but it should be done carefully. Use a full warm-up, set the safety stops correctly, and avoid testing a max if your form changes or your range of motion becomes shorter. An estimated max is often safer for tracking progress.
