Calorie Calculator

What is a Calorie?

A calorie is a unit of energy. In nutrition, the "calorie" we refer to is technically a kilocalorie (kcal) — the amount of energy needed to raise the temperature of 1 kilogram of water by 1°C. Your body requires a certain number of calories every day just to maintain basic functions like breathing, circulation, and cell repair — this is your Basal Metabolic Rate (BMR). When you add physical activity, your Total Daily Energy Expenditure (TDEE) is higher. The CalcSphere calorie calculator uses the scientifically validated Mifflin-St Jeor equation to estimate your personalized TDEE.

How to Use This Calculator

Enter your weight in kilograms and height in centimeters. Enter your age and select your gender. Then select your activity level from the dropdown — be honest here, as overestimating activity is the most common mistake people make. Click Calculate to see your TDEE — the calories you burn daily. You will also see targets for mild weight loss (−250 kcal), standard weight loss (−500 kcal, roughly 0.5 kg/week), aggressive loss (−1,000 kcal), and weight gain (+500 kcal).

💡 Pro Tips

• ✓A 500 calorie daily deficit creates roughly 0.5 kg of fat loss per week — this is the most sustainable rate.
• ✓Never eat below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision.
• ✓Protein has a high thermic effect — 20–30% of protein calories are burned in digestion itself.
• ✓Muscle burns more calories at rest than fat — strength training raises your BMR permanently.
• ✓Recalculate your TDEE every 4–6 weeks as your weight changes during a diet or fitness program.

Who Uses This Calculator?

People trying to lose weight use it to set daily calorie targets. Athletes and bodybuilders use it to calculate calorie needs for muscle gain. Dietitians use TDEE to create personalized meal plans. People with medical conditions like diabetes use it to understand energy requirements. Fitness coaches set nutrition targets for clients based on TDEE calculations. Anyone starting a diet or fitness journey should begin with their TDEE number.

Frequently Asked Questions