Leg Press 1RM Calculator

Enter the weight on the leg press and the reps you did to failure. The calculator estimates your one-rep max (1RM) with seven formulas and lists your leg press weights for 1 to 10 reps.

Leg press 1RM by plates per side

This table counts 45 lb plates only, the same number on each side, and leaves the sled out.

Counting the leg press sled

Leg press machines are not all alike. Reynolds et al., who tested one plate-loaded model, note that weight rooms have different types of leg press and advise against using their leg press equations on other machines. Whatever you enter, count it the same way every time: plates only, or plates plus the sled.

The choice changes the estimate by more than the sled's own weight, because the equations multiply the whole load. Take 360 lb of plates for 10 reps on a sled of 100 lb (an example figure; check your machine). Plates only, the estimate is 471.8 lb, or 571.8 lb once the sled is added back. Entered with the sled, 460 lb × 10 gives 602.8 lb, 31.0 lb more.

What a leg press study measured

Reynolds et al. (2006) tested 70 adults on one nonadjustable, plate-loaded Cybex leg press, lowering to a 90° angle checked with a goniometer on each rep. The load fell off faster with reps than on the bench press: as a share of the 1RM, the mean 5-rep max was 85.91% and the 10-rep max 70.10%, against 87.45% and 75.65% on the bench.

In their check, the Brzycki, Lander and O'Connor et al. equations underestimated leg press strength, and the Lombardi and Mayhew et al. equations were less accurate than all the linear ones. Every equation did worse from a 10-rep max than from a 5-rep max, so for the leg press a set of about 5 reps gives the better estimate. This page does not convert a leg press into a squat: we found no source for such a conversion that we could check.