Calorie Calculator

Calories are a measure of energy derived from food and beverages. Understanding your daily calorie needs is essential for maintaining, losing, or gaining weight. The number of calories you need depends on several factors including your age, gender, height, weight, and activity level.

How Calorie Needs Are Calculated

This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), which is the number of calories your body needs to function at rest. The equation is:

This BMR is then multiplied by an activity factor to determine your Total Daily Energy Expenditure (TDEE):

• Sedentary (little or no exercise): BMR × 1.2
• Lightly active (light exercise 1-3 days/week): BMR × 1.375
• Moderately active (moderate exercise 3-5 days/week): BMR × 1.55
• Very active (hard exercise 6-7 days/week): BMR × 1.725
• Extra active (very hard exercise & physical job): BMR × 1.9

Weight Management and Calorie Balance

To maintain your current weight, you need to consume approximately the same number of calories as your TDEE. For weight management:

• Weight loss: Consume fewer calories than your TDEE
• Weight gain: Consume more calories than your TDEE

A calorie deficit or surplus of approximately 500-1000 calories per day can lead to weight change of about 0.5-1 kg (1-2 pounds) per week, which is generally considered safe and sustainable.

Macronutrients

Calories come from three main macronutrients:

• Protein: 4 calories per gram - essential for building and repairing tissues, immune function, and enzyme production
• Carbohydrates: 4 calories per gram - primary energy source for the body and brain
• Fats: 9 calories per gram - necessary for hormone production, vitamin absorption, and cell health

The general recommendation for a balanced diet is:

• Protein: 10-35% of daily calories
• Carbohydrates: 45-65% of daily calories
• Fats: 20-35% of daily calories

However, optimal macronutrient distribution can vary based on individual factors, health conditions, and fitness goals.

Important Considerations

While this calculator provides a good estimate of your calorie needs, several factors can influence your actual requirements:

• Individual Metabolism: Metabolic rates can vary significantly between individuals
• Body Composition: Muscle tissue burns more calories than fat tissue
• Age: Metabolism typically slows as you age
• Health Conditions: Certain medical conditions and medications can affect metabolism
• Pregnancy and Breastfeeding: These states increase calorie needs

Note: This calculator provides estimates based on population averages. For personalized nutrition advice, consult with a healthcare provider, registered dietitian, or nutritionist.