---
title: "One Rep Max Calculator"
method: POST
path: "/api/v1/tools/one-rep-max-calculator"
tags: ["tools"]
---

# One Rep Max Calculator

`POST /api/v1/tools/one-rep-max-calculator`

## Request

- Base URL: `https://toolforte.com`
- URL: `https://toolforte.com/api/v1/tools/one-rep-max-calculator`
- Auth: HTTP bearer

Estimated one repetition maximum from a weight and reps, with percentages. Four formulas run side by side, Epley, Brzycki, Lombardi and O'Conner, and their average drives a training table from 95% down to 50% with the usual rep range for each load. This is an indication for training purposes, not medical advice.

## Request body

- object
  - `weight` integer
  - `reps` integer

## Response `200`

Successful result

- object
  - `ok` boolean
  - `data` object
    - `weight` integer
    - `reps` integer
    - `epley` number
    - `brzycki` number
    - `lombardi` number
    - `oconner` number
    - `average` number
    - `tested` boolean
    - `formulas` string[]
    - `percentages` object[]
      - `percent` integer
      - `weight` number
      - `reps` string
      - `focus` string
    - `note` string

## Other responses

- `400`: Missing or invalid request fields
- `401`: Invalid or missing API key
- `429`: Monthly plan limit reached

---

[API](https://skmtc.dev/toolforte/apis/toolforte-api.md) · [All operations](https://skmtc.dev/toolforte/apis/toolforte-api/llms.txt) · [OpenAPI document](https://skmtc.dev/toolforte/apis/toolforte-api/revisions/4d814d484dfc?raw)