How to Calculate Your Daily Calorie Needs
Knowing your daily calorie target is the foundation of any weight management goal โ whether you want to lose fat, build muscle, or simply maintain your current weight. This calculator uses the Mifflin-St Jeor equation, widely regarded by nutritionists as one of the most accurate methods for estimating metabolic rate.
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions โ breathing, circulation, cell production โ while completely at rest. It does not include any physical activity.
What is TDEE?
Total Daily Energy Expenditure (TDEE) takes your BMR and multiplies it by an activity factor based on how much you move during the day. This gives you your true maintenance calorie level โ eat this many calories and your weight stays stable.
Creating a Calorie Deficit or Surplus
A safe, sustainable rate of weight loss is about 0.5 kg per week, achieved through a 500 calorie/day deficit below your TDEE. Similarly, a 500 calorie surplus supports steady weight gain without excessive fat accumulation. Avoid deficits larger than 750-1000 kcal/day without medical supervision, as this can lead to muscle loss and nutrient deficiencies.
Frequently Asked Questions
How It Is Calculated
Mifflin-St Jeor: Men: BMR = 10W + 6.25H - 5A + 5. Women: BMR = 10W + 6.25H - 5A - 161. (W=kg, H=cm, A=age). TDEE = BMR x Activity Factor.
Worked Example
Sanjay, 35 years, 80kg, 175cm. BMR = 10x80 + 6.25x175 - 5x35 + 5 = 1,724 kcal/day. Moderately active (factor 1.55): TDEE = 2,672 kcal/day to maintain weight. For weight loss: 2,172 kcal/day (minus 500 = minus 0.5 kg/week).
Tips
BMR decreases ~2% per decade after 30 due to muscle loss. Strength training preserves muscle and keeps BMR higher. Protein intake of 1.0-1.2g per kg body weight preserves muscle during calorie deficit. Do not eat below BMR for extended periods.