Health Calculators

One Rep Max Calculator

Estimate one-rep max from weight and reps. The estimate updates in your browser as you type.

Estimated 1RM 215.833 lb

Local estimate.

What this tool is for

One Rep Max Calculator is built for wellness estimation inside health calculators when you need to estimates a max lift from weight and reps. It focuses on one rep max instead of making you adapt a broad calculator to a narrow task.

When to use it

Use it when weight lifted and reps are already known and you want a fast estimate before comparing options, checking a worksheet, or copying the result into another workflow.

Inputs

  • Weight lifted is one of the direct inputs used to calculate one rep max. Use lb for this field.
  • Reps is one of the direct inputs used to calculate one rep max. Use reps for this field.

Formula

1RM = weight x (1 + reps / 30)

Example

185 lb for 5 reps estimates about 215.83 lb.

What the result means

The result labeled "One Rep Max" is the direct output of 1RM = weight x (1 + reps / 30). In the worked example, 185 lb for 5 reps estimates about 215.83 lb.

Before you rely on the result

This is a general wellness estimate, not medical advice, diagnosis, or a treatment recommendation.