A calorie calculator determines your daily calorie needs based on your age, gender, weight, height, and activity level. It calculates your Basal Metabolic Rate (BMR) - the calories you burn at rest - and Total Daily Energy Expenditure (TDEE) - your total calories burned including physical activity. This tool is essential for weight management, fitness goals, and nutrition planning.

BMR (Basal Metabolic Rate) is the number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production. TDEE (Total Daily Energy Expenditure) accounts for your activity level by multiplying BMR by an activity factor. TDEE represents your maintenance calories - eat this amount to maintain current weight. Understanding both metrics helps create effective diet plans.

Enter your age, gender, weight, and height. Select your activity level from sedentary to very active. Choose your goal: weight loss, maintenance, or weight gain. The calculator uses proven formulas (Mifflin-St Jeor) to compute your BMR and TDEE, then provides personalized calorie targets based on your goal. Results include macronutrient recommendations for optimal nutrition.

Sedentary: Little to no exercise, desk job. Light Activity: Exercise 1-3 days/week, light walking. Moderate Activity: Exercise 3-5 days/week, moderate cardio. Very Active: Exercise 6-7 days/week, intense training. Extra Active: Athlete, physical job plus intense training. Accurately assessing your activity level ensures precise calorie recommendations. Most people overestimate their activity level.

To lose weight, create a calorie deficit by consuming fewer calories than your TDEE. A deficit of 500 calories daily results in approximately 0.5 kg (1 lb) weight loss per week. A 1000 calorie deficit yields 1 kg (2 lbs) weekly loss. Never drop below 1200 calories (women) or 1500 calories (men) to avoid nutritional deficiencies. Sustainable weight loss combines moderate calorie reduction with regular exercise.

Building muscle requires a calorie surplus - consuming more than your TDEE. A surplus of 200-500 calories daily supports muscle growth while minimizing fat gain. Combine surplus calories with strength training and adequate protein (1.6-2.2g per kg body weight). Bulk too aggressively and you'll gain excess fat. Track progress weekly and adjust intake based on results and body composition changes.

Macronutrients (protein, carbohydrates, fats) should be balanced for optimal health. Protein: 10-35% of calories (higher for athletes, 1.6-2.2g/kg). Carbohydrates: 45-65% of calories (fuel for energy). Fats: 20-35% of calories (essential for hormones). Athletes may need higher protein. Low-carb dieters reduce carbs to 5-20%. The calculator provides macro targets based on your goals and activity level.

Weigh yourself consistently (same time, same conditions). Track calories accurately using a food scale and app. Be honest about activity levels - most overestimate. Recalculate every 4-6 weeks as weight changes. Account for non-exercise activity (NEAT). Monitor progress through measurements, not just scale weight. Adjust calorie intake based on results. Remember: calculators provide estimates; individual metabolism varies. Listen to your body and adjust accordingly.