# One Rep Max Calculator

> Estimate one-repetition maximum with seven established formulas or their average and generate a percentage-based training table.

Page: https://askcalculators.com/calculator/one-rep-max-calculator/
Definition: https://askcalculators.com/calculator/one-rep-max-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/one-rep-max-calculator/schema.json
Version: 2.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/one-rep-max-calculator/?unitSystem=lb&liftedWeight=135&repetitions=5&formula=average

## Inputs
- unitSystem: Weight units; type=select; required; default=lb; values=lb|kg
- liftedWeight: Weight lifted; type=number; required; default=135; min=0.1; max=5000
- repetitions: Repetitions completed; type=number; required; default=5; min=1; max=20
- formula: Formula; type=select; required; default=average; values=average|epley|brzycki|lombardi|lander|mayhew|oconner|wathan

## Outputs
- oneRepMax: Estimated one-rep max; format=number; primary
- epley: Epley estimate; format=number
- brzycki: Brzycki estimate; format=number
- formulaSpread: Formula range; format=text

## Formula
Examples: Epley 1RM = w(1+r/30); Brzycki 1RM = 36w/(37−r); other selected equations apply published repetition coefficients.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: Estimated 1RM is not a recommendation to attempt a maximal lift. Use appropriate technique, supervision, and load progression.