Calorie Intake Calculator

How to Calculate Daily Calorie Needs

Calculating your daily calorie needs is essential for maintaining, losing, or gaining weight. It involves determining your Basal Metabolic Rate (BMR) and adjusting it based on your activity level.

Calorie Needs Formula

We use the Mifflin-St Jeor Equation to calculate BMR, then multiply it by an activity factor:

For males: $$BMR = 10 * weight + 6.25 * height - 5 * age + 5$$

For females: $$BMR = 10 * weight + 6.25 * height - 5 * age - 161$$

Then: $$TDEE = BMR * Activity Factor$$

Where:

• Weight is in kilograms
• Height is in centimeters
• Age is in years
• TDEE is Total Daily Energy Expenditure

Calculation Steps

1. Calculate BMR using the appropriate formula based on sex
2. Determine the activity factor based on lifestyle
3. Multiply BMR by the activity factor to get TDEE
4. The result is the estimated daily calorie needs

Example Calculation

Let's calculate the daily calorie needs for a 30-year-old female who is 165 cm tall, weighs 60 kg, and has a moderately active lifestyle.

Step 1: Calculate BMR

$$\begin{align} BMR &= 10 * 60 + 6.25 * 165 - 5 * 30 - 161 \\ &= 600 + 1031.25 - 150 - 161 \\ &= 1320.25 \text{ calories} \end{align}$$

Step 2: Apply activity factor (moderately active = 1.55)

$$\begin{align} TDEE &= 1320.25 * 1.55 \\ &= 2046.39 \text{ calories} \end{align}$$

Therefore, this person needs approximately 2046 calories per day to maintain their current weight.

Visual Representation

This graph illustrates the activity factors used to adjust BMR based on different activity levels. A higher activity level corresponds to a higher activity factor, resulting in increased daily calorie needs.