BMR & Calorie API
Energy-expenditure and nutrition maths as an API, computed locally and deterministically. The bmr endpoint computes the basal metabolic rate — the calories the body burns at rest — from weight, height, age and sex, using the modern Mifflin-St Jeor equation (BMR = 10·kg + 6.25·cm − 5·age + 5 for men, −161 for women) and reporting the classic revised Harris-Benedict value alongside for comparison. The tdee endpoint computes the total daily energy expenditure, TDEE = BMR × an activity factor from sedentary (1.2) to very active (1.9), and the goal calories for maintenance, mild and standard weight loss and weight gain — a 500 kcal/day deficit or surplus is about 0.45 kg per week. The macros endpoint splits a calorie target into protein, fat and carbohydrate grams, with protein set per kilogram of bodyweight (4 kcal/g protein and carbs, 9 kcal/g fat). Everything is computed locally and deterministically, so it is instant and private. Ideal for fitness, nutrition and health-app developers, diet and meal-planning tools, gym and coaching apps, and wellness dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. Estimates only, not medical advice. 3 endpoints. This is metabolic-rate and calorie maths; for body-mass-index use a BMI calculator.
api.oanor.com/bmr-api