Calorie Calculator — Free Online Calorie Calculator

Calculate daily calorie needs based on activity level

About Calorie Calculator

Calories measure the energy your body gets from food and expends through activity. Your daily calorie needs depend on your Basal Metabolic Rate (BMR) - calories burned at rest - and your activity level. Understanding your calorie needs helps with weight management and overall health.

Formula

TDEE = BMR × Activity Multiplier

How It Works

  1. Calculate BMR using the Mifflin-St Jeor equation
  2. Multiply BMR by activity factor to get TDEE
  3. Subtract 500 calories/day for ~1 lb weight loss per week
  4. Add 250-500 calories/day for weight gain

Examples

CalculationExpressionResult
Sedentary male30 yr, 70 kg, 175 cm2,058 cal/day
Active female25 yr, 60 kg, 165 cm2,281 cal/day
Weight lossMaintenance - 500-0.5 kg/week

Tips

  • BMR decreases with age and lower muscle mass
  • Protein requires more calories to digest than fats or carbs
  • Don't drop below 1200 calories without medical supervision

Frequently Asked Questions

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is calories burned at complete rest for basic body functions. TDEE (Total Daily Energy Expenditure) includes all daily activities. TDEE = BMR × activity factor. For weight management, focus on TDEE as it represents your true daily needs.

How many calories should I eat to lose weight?

A deficit of 500 calories per day typically results in about 1 pound of weight loss per week. Calculate your TDEE and subtract 500. Don't go below 1200 (women) or 1500 (men) calories without medical supervision, as this can slow metabolism and cause nutrient deficiencies.

How accurate are calorie calculations?

Formulas provide estimates that can be 10-15% off for individuals. Factors like genetics, hormones, and gut bacteria affect actual metabolism. Use calculations as starting points and adjust based on real-world results over 2-4 weeks.

Do calories matter more than food quality?

Both matter. For weight change, calories are primary - you can lose weight eating only junk food (though it's not healthy). For overall health, nutrition quality matters immensely. A balanced approach considers both calorie quantity and food quality.

How does activity level affect calorie needs?

Activity multipliers range from 1.2 (sedentary) to 1.9+ (very active). A sedentary person with 1800 BMR needs ~2160 calories. The same person with intense daily exercise might need ~3420 calories. Accurately assessing activity level is crucial for correct calculations.

What is the thermic effect of food?

Thermic effect is calories burned digesting food, about 10% of intake. Protein has the highest thermic effect (20-30%), followed by carbs (5-10%) and fats (0-3%). This is why high-protein diets can slightly boost calorie burning.

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