About Calories.run

The Origin

Hi, I'm Ashwini Yadav, a web developer and digital entrepreneur based in Mumbai, Maharashtra, India. I built Calories.run out of pure frustration with the state of the modern health web.

If you've ever tried to calculate your total daily energy expenditure or figure out how many calories you burned running a 5K, you've likely encountered the same bloated, ad-heavy fitness sites I did. They are agonizingly slow, force you to create user accounts, hide basic math behind paywalls, and bombard you with popups.

I believe that access to your own metabolic data should be frictionless, instantaneous, and private. That's why Calories.run operates entirely on client-side Vanilla JavaScript. There is no server latency, no database storing your weight or body fat percentage, and no login required. The moment you input your metrics, the browser executes the math locally.

The Science (Why You Can Trust Our Math)

In the health and fitness space, trust is paramount. A single miscalculation in a calorie deficit can stall weeks of hard work. That is why we do not invent math. Every calculator on this domain relies exclusively on peer-reviewed, empirically validated formulas deployed by registered dietitians and sports scientists worldwide.

• Human Metabolism (BMR/TDEE): We use the clinical gold-standard Mifflin-St Jeor equation for the general population. If you input your Body Fat Percentage, our engine automatically dynamically switches to the Katch-McArdle formula, utilizing lean body mass for elite athlete accuracy.
• Veterinary Nutrition: Our dog and cat calorie calculators strictly follow the World Small Animal Veterinary Association (WSAVA) global nutrition guidelines for resting energy requirements (RER).
• Cycling & Athletics: We utilize Dr. Andrew Coggan's power profiling models for cycling (W/kg) and Pete Riegel's endurance formulas for our track event predictors.
• Food & Nutrition Data: The comprehensive macronutrient profiles and calorie counts in our Food Calorie Database are sourced directly from the U.S. Department of Agriculture (USDA) FoodData Central.

When you use Calories.run to calculate your macros or plan your diet, you are using the exact mathematical models deployed by clinical nutritionists globally.