How Are Calories Calculated? (Mifflin-St Jeor Formula)
Our calculator uses the Mifflin-St Jeor equation, the most accurate BMR formula validated by clinical research:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
This gives your Basal Metabolic Rate (BMR) — calories burned at complete rest. To get your TDEE (Total Daily Energy Expenditure), multiply BMR by your activity factor (1.2 to 1.9).
Calorie Deficit for Weight Loss
A 500 calorie/day deficit leads to approximately 0.45 kg (1 lb) of fat loss per week. A 1,000 calorie deficit leads to ~0.9 kg/week. However, never go below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision — extreme restriction causes muscle loss and metabolic slowdown.
Why Calories Alone Don't Tell the Full Story
Food quality matters as much as quantity. 200 calories from almonds provides healthy fats, fiber, and protein that keep you full for hours. 200 calories from a sugary drink spikes blood sugar and leaves you hungry in 30 minutes. Focus on protein-rich, high-fiber whole foods that naturally control hunger within your calorie budget.
Frequently Asked Questions
How many calories should I eat per day to lose weight?
Eat 300–500 calories below your TDEE for gradual, sustainable weight loss of 0.25–0.5 kg per week. Avoid cutting more than 1,000 calories below TDEE as it causes muscle loss, fatigue, and metabolic adaptation. A modest deficit sustained over months is more effective than extreme restriction.
What is BMR vs TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep organs functioning. TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through activity, digestion (thermic effect), and NEAT (non-exercise activity). TDEE is the number you use for weight management.
How many calories in common Indian foods?
1 medium chapati: ~70 kcal. 1 cup cooked rice: ~200 kcal. 1 cup dal: ~150 kcal. 100g chicken breast: ~165 kcal. 1 medium banana: ~90 kcal. 1 cup full-fat milk: ~150 kcal. 1 tbsp ghee: ~112 kcal.
Does exercise increase calorie needs?
Yes. Exercise increases TDEE, which is why the activity multiplier matters. Running 5 km burns roughly 300–400 calories. Strength training burns 200–400 calories during the session plus additional calories post-workout through muscle repair (EPOC effect). Select the appropriate activity level in the calculator for an accurate estimate.