Leg Press 1RM Calculator

Your leg press max and working weights

Use this estimate only on the same leg-press machine, seat position, range of motion and weight-counting method. Record those setup details before comparing another workout.

How to count weight for leg press

Enter a completed set from the same leg-press machine or model, seat and footplate setup, and choose whether your recorded weight is plates only or includes a confirmed starting value. Keep that choice, the unit, and any machine notes with the result.

A leg-press number changes meaning when the machine, sled, setup, angle correction, or weight-counting convention changes. This calculator keeps the recorded convention and does not add a sled-angle transformation or convert the result to another lift.

Weight unit

Choose the unit shown on your weights.

Weight lifted

Enter the weight used for your completed set, following the weight convention below.

Repetitions completed

Enter 1–10 full repetitions from a hard set with consistent technique.

Repetitions to estimate

Choose how many repetitions you want to estimate a weight for, from 1 to 10.

Percentage of your estimated max

Enter the percentage weight you want to calculate.

Available weight increase

Leave blank for the exact estimate, or enter the smallest total weight increase your equipment allows.

How are you counting the weight?

Choose the description that matches the number you entered. Keep this choice the same when comparing results.

Machine name

Optionally name the exact machine so you can compare like-for-like next time.

Setup notes

Record the seat, grip or stance you want to repeat next time.

Estimated leg press weights across repetition targets

The curve is a same-machine comparison across rep targets. It does not compensate for rail angle, friction, leverage or a different machine design.

The example below shows how to read the graph. Your graph updates after you calculate, and the complete values remain available in the table beneath it.

How this leg press estimate is calculated

The result uses only the values you enter and the method shown below. Rounded workout values stay separate from the underlying calculation.

A checked leg press example

This checked example uses pounds. It comes directly from the same calculator that produces your result.

Select “Use example” to load these values. If you choose kilograms in the calculator, the chart and personalized tables recalculate in kilograms.

Method and equipment limits for leg press

Use this as a repeatable estimate, not proof of your true one-rep max. The available study used to check the Brzycki equation tested free-weight bench press in 103 college women. That study checks the equation in that setting; It did not test leg press. Leg-press machines can differ in sled angle, leverage and starting resistance, so compare results only on the same machine and setup. Use a hard set of 1–10 full repetitions. Stopping early can understate the estimate, and this calculator does not accept higher-repetition sets.

• Strength Testing—Predicting a One-Rep Max from Reps-to-Fatigue — Matt Brzycki (1993).
• Accuracy of Prediction Equations for Determining One Repetition Maximum Bench Press in Women Before and After Resistance Training — Mayhew et al. (2008).
• Guide for the Use of the International System of Units (SI) — NIST (2008).

Choose a related leg press task

• Leg Press (45° Sled) Live Endura

  Explore leg-press standards while checking that page's equipment convention.

• Leg Press Weight and Resistance Calculator

  Check what your leg-press weight includes before estimating a rep max.

• RPE Calculator

  Add an effort description to the completed leg-press set.

• Warm-Up Set Calculator

  Calculate selected warm-up percentages for the same machine.

• Hack Squat 1RM Calculator

  Keep a hack-squat estimate as a separate machine record rather than transferring this max.