Calorie Calculator
Calculate your daily calorie needs based on activity level.
How to Use the Calorie Calculator
This calculator uses the Mifflin-St Jeor equation, which is the most widely accepted formula for estimating Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). It requires your age, gender, height, weight, and activity level to produce results.
BMR vs. TDEE
BMR (Basal Metabolic Rate) is the number of calories your body needs to maintain basic physiological functions at rest — breathing, circulation, cell production, and organ function. It's the minimum calorie intake needed if you were lying in bed all day and doing nothing else.
TDEE (Total Daily Energy Expenditure) accounts for your activity level on top of your BMR. It's the actual number of calories you burn in a day given your lifestyle. To maintain your current weight, you should consume approximately this many calories per day.
Calorie Goals
- Lose weight fast: TDEE − 1,000 cal/day. Creates a 1,000 calorie deficit, theoretically leading to about 2 lbs/week weight loss. Not recommended for extended periods.
- Lose weight: TDEE − 500 cal/day. Creates a 500 calorie deficit for sustainable ~1 lb/week weight loss.
- Maintain: Consume at TDEE to maintain current weight.
- Gain weight: TDEE + 500 cal/day for approximately 1 lb/week weight gain.
These are estimates based on averages. Individual metabolism varies. Consult a registered dietitian for personalized nutritional guidance.
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Frequently Asked Questions
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation, developed in 1990, is considered the most accurate formula for estimating BMR in modern research. For men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5. For women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161. It's more accurate than the older Harris-Benedict equation and is currently recommended by the American Dietetic Association.
How accurate are these calorie estimates?
BMR and TDEE formulas are estimates with a typical margin of error of ±10–15% for most people. Factors that affect actual metabolic rate include muscle mass (higher = faster metabolism), body fat percentage, genetics, hormonal health, medications, and ambient temperature. Track your actual intake and weight for 2–4 weeks to calibrate your personal TDEE accurately.
How many calories should I eat to lose weight safely?
A safe and sustainable weight loss rate is 0.5–1 kg (1–2 lbs) per week, which requires a daily deficit of 500–1,000 calories below your TDEE. Most health organizations recommend not going below 1,200 calories/day for women or 1,500 calories/day for men, as very low intakes can cause nutrient deficiencies and metabolic adaptation. Always consult a doctor before beginning a significant calorie restriction.
Which activity level should I choose?
Most people underestimate their activity level when choosing from these categories. Sedentary (1.2x) is for desk workers who do no deliberate exercise. Light (1.375x) is for those with a desk job who exercise 1–2 times per week. Moderate (1.55x) is for those who work out 3–4 times per week at moderate intensity. Very Active (1.725x) is for athletes or people with physically demanding jobs plus workouts. When in doubt, choose one level lower than you think to avoid overestimating.
Does this account for macro breakdown?
No — this calculator only provides total calorie targets. Macronutrient ratios (protein, carbohydrates, fat) depend on your specific goals. Common guidelines: for weight loss, aim for 25–35% of calories from protein to preserve muscle. For muscle gain, 30–40% protein. General health guidelines suggest roughly 45–65% carbs, 20–35% fat, and 10–35% protein, but these vary widely by individual need, medical conditions, and dietary preferences.