Basis of the Calculator
The calorie calculator is designed to estimate the number of calories a person needs to maintain their current weight based on their Basal Metabolic Rate (BMR) and their activity level. The BMR represents the number of calories required to keep your body functioning at rest, while the Total Daily Energy Expenditure (TDEE) accounts for physical activities.
Formulas Used
1. Basal Metabolic Rate (BMR):
- Mifflin-St Jeor Equation: This is one of the most accurate equations for calculating BMR.
– For men: BMR=88.362+(13.397×weight in kg)+(4.799×height in cm)−(5.677×age in years)
– For women: BMR=447.593+(9.247×weight in kg)+(3.098×height in cm)−(4.330×age in years)
2. Total Daily Energy Expenditure (TDEE):
TDEE is calculated by multiplying the BMR by an activity factor that corresponds to the user’s level of physical activity:
- Sedentary (little or no exercise): BMR × 1.2
- Lightly active (light exercise/sports 1-3 days/week): BMR × 1.375
- Moderately active (moderate exercise/sports 3-5 days/week): BMR × 1.55
- Very active (hard exercise/sports 6-7 days a week): BMR × 1.725
- Super active (very hard exercise/physical job): BMR × 1.9
Other Information
1. Units Conversion:
Weight: The calculator supports both metric (kg) and US (lbs) units.
- Conversion from pounds to kilograms: weight in kg=weight in lbs×0.453592
Height: The calculator supports both metric (cm) and US (feet and inches) units.
- Conversion from feet and inches to centimeters: height in cm=(height in feet×30.48)+(height in inches×2.54)
2. Input Fields:
- Age: Number of years.
- Gender: Male or Female.
- Weight: Depending on the selected units, either in kilograms or pounds.
- Height: Depending on the selected units, either in centimeters or feet and inches.
- Activity Level: User selects their level of physical activity from predefined categories.
3. User Experience:
- The calculator is designed to be responsive, ensuring usability on various devices, including desktops, tablets, and smartphones.
- Input validation ensures that all required fields are filled out correctly before performing the calculation.
Example Calculation
Suppose a user enters the following details:
- Age: 25
- Gender: Male
- Weight: 70 kg
- Height: 175 cm
- Activity Level: Moderately active
The BMR calculation would be:
BMR=88.362+(13.397×70)+(4.799×175)−(5.677×25)=1766.17calories/day
The TDEE for a moderately active lifestyle would be: TDEE=1766.17×1.55=2737.56calories/day
Thus, the user would need approximately 2738 calories per day to maintain their current weight.
Summary
The calorie calculator provides a user-friendly way to estimate daily calorie needs based on scientifically validated formulas. It considers individual differences in age, gender, weight, height, and activity level to provide a personalized estimate. By offering both metric and US units, it ensures accessibility and convenience for a diverse user base.