Calorie Calculator
Calculate daily calorie needs (BMR and TDEE)
How to use Calorie Calculator
Calculate your daily calorie needs based on BMR and activity level (TDEE). Weight goals supported. Free online calorie calculator.
Why calculate your daily calorie needs?
Calories are units of energy. Your body needs a specific amount each day just to maintain basic functions (breathing, circulation, cell repair) plus extra for physical activity. Understanding your needs is the foundation of evidence-based nutrition.
- Weight loss: A deficit of 500 calories per day below TDEE leads to approximately 0.5kg (1lb) of fat loss per week — a sustainable rate. Larger deficits risk muscle loss and metabolic adaptation.
- Weight gain (muscle building): A surplus of 200-500 calories above TDEE, combined with resistance training, supports muscle growth with minimal fat gain.
- Weight maintenance: Eating at TDEE maintains current weight. TDEE fluctuates with activity level — more active days need more food.
- Meal planning: Distribute daily calorie targets across meals and snacks. Knowing your target helps evaluate food choices realistically.
- Medical nutrition: Dietitians use BMR/TDEE as a starting point for clinical nutrition plans for patients with specific health conditions.
BMR vs TDEE: BMR (Basal Metabolic Rate) is calories burned at complete rest — keeping you alive. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor: sedentary (×1.2), lightly active (×1.375), moderately active (×1.55), very active (×1.725), extra active (×1.9).
Frequently Asked Questions
Which BMR formula is most accurate — Mifflin-St Jeor or Harris-Benedict?
The Mifflin-St Jeor equation (1990) is generally considered more accurate for modern populations. The original Harris-Benedict equations (1919, revised 1984) tend to overestimate BMR slightly. The Katch-McArdle formula is most accurate if you know your lean body mass. This calculator uses Mifflin-St Jeor.
How accurate is TDEE calculation?
TDEE calculators give estimates with roughly ±20% accuracy. Activity multipliers are the main source of error — people consistently overestimate their activity level. Start with the calculated TDEE, track weight for 2-3 weeks, and adjust if reality differs from prediction.
Does eating less always lead to weight loss?
Not indefinitely. The body adapts to prolonged calorie restriction through metabolic adaptation — lowering BMR to match reduced intake. This is why very low-calorie diets plateau. Cycling calories, diet breaks, and preserving muscle mass through resistance training help maintain metabolic rate during weight loss.
How do macronutrients relate to calories?
Protein: 4 calories per gram. Carbohydrates: 4 calories per gram. Fat: 9 calories per gram. Alcohol: 7 calories per gram. A 2,000 calorie diet might be 150g protein (600 cal), 200g carbs (800 cal), and 67g fat (600 cal). Macronutrient ratios affect body composition, satiety, and performance beyond just total calories.
Should I eat back exercise calories?
It depends on how your TDEE was calculated. If using an activity multiplier that already accounts for exercise, do not eat back calories. If using sedentary TDEE as a base and adding exercise on top, eating back some exercise calories prevents too large a deficit. In practice, fitness trackers overestimate burn — eating back 50-75% of tracked exercise calories is a common approach.
Calorie calculator vs macro calculator vs food tracking app
A calorie calculator estimates your daily energy need — the target number. A macro calculator further breaks this into protein, carbohydrate, and fat targets in grams. A food tracking app (MyFitnessPal, Cronometer, Lose It) logs actual food consumed and compares to targets. The calculator sets the goal; the app tracks progress. For serious nutrition management, all three work together: calculate needs, set macro targets, track intake.