#bmi

Body-composition maths as an API, computed locally and deterministically. The bmi endpoint computes the body mass index, BMI = weight/height², classifies it on the WHO scale (underweight, normal, overweight, obese) and returns the healthy weight range for the person's height. The idealweight endpoint computes the ideal body weight by the four classic formulas — Devine, Robinson, Miller and Hamwi — each a base weight plus an increment for every inch of height above five feet, and their average. The bodyfat endpoint estimates body-fat percentage by the US Navy circumference method from the neck and waist (and hip for women) and the height, classifies it from essential to high, and — given a weight — splits it into fat mass and lean mass. Everything is computed locally and deterministically, so it is instant and private. Ideal for fitness, health and wellness app developers, body-tracking and coaching tools, gym and clinic dashboards, and self-assessment apps. Pure local computation — no key, no third-party service, instant. Live, nothing stored. Estimates only, not medical advice. 3 endpoints. This is body composition; for basal metabolic rate and calories use a BMR API.

api.oanor.com/bmi-api

A complete health & fitness calculator suite in one API: Body Mass Index with category and healthy-weight range, Basal Metabolic Rate (Mifflin-St Jeor and Harris-Benedict), Total Daily Energy Expenditure with weight-loss/gain calorie targets, macronutrient splits (balanced, low-carb, high-protein, keto, endurance) with fibre, U.S. Navy body-fat percentage, ideal body weight across four classic formulas (Devine, Robinson, Miller, Hamwi), and daily water intake. Every endpoint accepts GET query parameters or a JSON POST body and works in both metric and imperial units. All computation is done locally with established public-domain equations, so responses are instant and the service is always available. Ideal for fitness trackers, nutrition apps, telehealth and wellness dashboards.

api.oanor.com/healthcalc-api