Calorie Calculator - Track Your Daily Energy Needs

Calorie Calculator

Calculate Your Daily Calorie Needs

Your Results

Basal Metabolic Rate (BMR): 0 calories/day

Total Daily Energy Expenditure (TDEE): 0 calories/day

Recommended Daily Calories: 0 calories/day

Purpose of the Calorie Calculator

This calorie calculator helps you determine how many calories you need each day to maintain, lose, or gain weight based on your personal metrics and activity level. Understanding your daily caloric needs is fundamental to achieving any health or fitness goal, whether you want to lose fat, build muscle, or simply maintain your current weight.

The calculator provides three important metrics:

  • Basal Metabolic Rate (BMR): The number of calories your body needs at complete rest to maintain basic functions like breathing and circulation.
  • Total Daily Energy Expenditure (TDEE): Your BMR plus calories burned through daily activities and exercise.
  • Recommended Daily Calories: Adjusted based on your specific weight goal (maintain, lose, or gain).

Real-World Examples

Example 1 - Weight Loss: Sarah is a 35-year-old woman who weighs 70kg and is 165cm tall. She works an office job and exercises 2-3 times per week (lightly active). To lose weight safely (about 0.5kg per week), she should consume about 1,700 calories per day instead of her maintenance 2,200 calories.

Example 2 - Muscle Gain: Mark is a 25-year-old man who weighs 75kg and is 180cm tall. He lifts weights 5 times per week (very active) and wants to gain muscle. His calculator recommends about 3,100 calories per day for gradual muscle gain.

Example 3 - Maintenance: A 45-year-old moderately active man (exercises 3-4 times per week) who weighs 80kg and is 175cm tall needs about 2,600 calories per day to maintain his current weight.

Formulas and Algorithms

The calculator uses the Mifflin-St Jeor Equation, considered the most accurate for calculating BMR in most adults:

For Men:

BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5

For Women:

BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

TDEE is calculated by multiplying BMR by the activity factor:

  • Sedentary (little or no exercise): BMR × 1.2
  • Lightly active (light exercise 1-3 days/week): BMR × 1.375
  • Moderately active (moderate exercise 3-5 days/week): BMR × 1.55
  • Very active (hard exercise 6-7 days/week): BMR × 1.725
  • Extra active (very hard exercise & physical job): BMR × 1.9

For weight goals, we adjust TDEE:

  • Weight loss: TDEE - 500 calories (for about 0.5kg loss per week)
  • Weight gain: TDEE + 500 calories (for about 0.5kg gain per week)
  • Maintenance: TDEE (no adjustment)

Privacy Note

This calorie calculator processes all data locally in your browser. No personal information is collected, stored, or transmitted to any servers. Your weight, age, height, and other metrics never leave your device, ensuring complete privacy and security.

Frequently Asked Questions

How accurate is this calorie calculator?

While the Mifflin-St Jeor equation is currently the most accurate BMR formula for most people, individual variations in metabolism can cause results to differ by ±10-15%. Consider the calculator's results as a good starting point that you may need to adjust based on your actual results over time.

Why does my calorie need change with age?

Metabolism naturally slows with age due to decreasing muscle mass and hormonal changes. The calculator accounts for this by including age in the BMR formula, which explains why two people with identical height and weight but different ages will have different calorie requirements.

How should I adjust my calories if I'm not seeing results?

If after 2-3 weeks you're not seeing expected weight changes, adjust your calories by 100-200 per day (up or down depending on your goal). Track changes for another 2 weeks before making further adjustments. Remember that weight loss/gain isn't linear and can fluctuate daily.

Can I use this calculator if I'm pregnant or breastfeeding?

This calculator is not designed for pregnancy or breastfeeding, which significantly alter calorie needs. Consult your healthcare provider for personalized nutrition advice during these periods.

How often should I recalculate my calorie needs?

Recalculate whenever your weight changes by more than 5kg, your activity level changes significantly, or every 6 months to account for natural metabolic changes. If you're actively losing weight, recalculate every 4-5kg lost.

What's the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) represents calories needed for basic bodily functions at complete rest. TDEE (Total Daily Energy Expenditure) includes all your daily activities and exercise. TDEE is typically 20-50% higher than BMR depending on activity level.