tdee-calculator-js

A lightweight, dependency-free JavaScript utility for calculating Total Daily Energy Expenditure (TDEE), Basal Metabolic Rate (BMR), calorie targets, and macronutrient splits.

Built by the team behind Free TDEE Calculator, the free web-based toolkit for daily calorie and macro planning.

Installation

npm install tdee-calculator-js

Usage

const { calculateTDEEProfile } = require('tdee-calculator-js');

const result = calculateTDEEProfile({
  weightKg: 75,
  heightCm: 180,
  age: 28,
  gender: 'male',
  activityLevel: 'moderate', // sedentary | light | moderate | active | veryActive
});

console.log(result);
// {
//   bmr: 1740,
//   tdee: 2697,
//   targets: { cut: 2158, maintain: 2697, bulk: 2967 },
//   macros: { calories: 2697, proteinG: 150, carbsG: 337, fatG: 84 }
// }

Individual functions

const {
  calculateBMR,      // Mifflin-St Jeor (default), Harris-Benedict, Katch-McArdle
  calculateTDEE,     // BMR x activity multiplier
  calculateTargets,  // cut / maintain / bulk calories
  calculateMacros,   // protein / carbs / fat grams
} = require('tdee-calculator-js');

// Katch-McArdle needs body fat percentage
calculateBMR({ weightKg: 80, heightCm: 182, age: 30, gender: 'male', bodyFatPct: 15, formula: 'katch' });

Formulas

• Mifflin-St Jeor (default): the most accurate widely validated BMR equation for healthy adults.
• Harris-Benedict (revised 1984 version) also supported.
• Katch-McArdle: BMR from lean body mass, ideal for lifters who know their body fat percentage.

For a fully interactive version of these formulas with visual macro breakdowns and step-by-step guidance, try the Free TDEE Calculator web app, including the detailed macro calculator.

Activity levels

| Level | Multiplier | Meaning | |---|---|---| | sedentary | 1.2 | Little or no exercise, desk job | | light | 1.375 | Light exercise 1-3 days/week | | moderate | 1.55 | Moderate exercise 3-5 days/week | | active | 1.725 | Hard exercise 6-7 days/week | | veryActive | 1.9 | Very hard daily exercise or physical job |

License

MIT