Scientific Calorie Calculator
Calculate your daily energy needs to reach your weight goals.
*Note: For safety, it is generally recommended not to consume fewer than 1,200 calories (women) or 1,500 calories (men) per day.
Understanding Your Calorie Needs for Weight Loss
To lose weight, you must create a calorie deficit—consuming fewer calories than your body burns. This calculator uses the Mifflin-St Jeor Equation, widely considered the most accurate formula for estimating your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
What is BMR and TDEE?
BMR (Basal Metabolic Rate): This is the number of calories your body needs to function at rest (breathing, circulating blood, and cell production). It doesn't include physical activity.
TDEE (Total Daily Energy Expenditure): This is the total number of calories you burn in a day, including exercise and daily movement. To maintain your weight, your "Calories In" should equal your TDEE.
Realistic Weight Loss Example
Imagine a 35-year-old male, 180 cm tall, weighing 95 kg, with a "Moderately Active" lifestyle.
- His TDEE: ~3,050 calories/day (to stay the same weight).
- For Weight Loss: To lose 0.5 kg per week, he should consume approximately 2,550 calories.
- For Faster Loss: To lose 1 kg per week, he would target 2,050 calories.
The Science of the Calorie Deficit
One pound of fat is approximately 3,500 calories (roughly 7,700 calories per kilogram). By reducing your daily intake by 500 calories below your maintenance level, you create a deficit of 3,500 calories over 7 days, leading to approximately 0.5 kg of weight loss per week.
Important Safety Considerations
While a deficit is necessary for weight loss, "more" is not always better. Cutting calories too aggressively can lead to muscle loss, nutrient deficiencies, and a metabolic slowdown. Health professionals recommend aiming for a gradual loss of 0.5 to 1 kg per week for sustainable results.