How to Calculate Your Caloric Needs Using the Mifflin-St Jeor Equation

Knowing how many calories your body needs is essential for maintaining a healthy diet and achieving your weight goals. Fortunately, there is a reliable formula called the Mifflin-St Jeor equation that can help you calculate your caloric needs accurately. By understanding this equation and applying it to your lifestyle, you can make informed decisions about your diet and nutrition.

The Mifflin-St Jeor equation is a widely used method for determining resting metabolic rate (RMR), which is the number of calories your body requires to perform basic functions while at rest. RMR accounts for about 60-75% of your overall calorie expenditure. Once you know your RMR, you can then factor in your activity level to determine your total daily energy expenditure (TDEE) and tailor your caloric intake to your goals.

Step-by-Step Guide

1. Determine your gender: The formula differs slightly for males and females. Remember to use the appropriate equation for your gender.
2. Record your weight: Your weight in kilograms will be used in the equation. If you know your weight in pounds, divide it by 2.2046 to convert it to kilograms.
3. Measure your height: Your height should be recorded in centimeters. If you know your height in inches, multiply it by 2.54 to convert it to centimeters.
4. Note your age: Your age in years will be used in the equation.
5. Plug the values into the equation:

For males: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5

For females: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

6. Adjust for activity level: Multiply your RMR by an appropriate activity factor to estimate your TDEE.

• Sedentary (little or no exercise): RMR × 1.2
• Lightly active (light exercise/light sports 1-3 days/week): RMR × 1.375
• Moderately active (moderate exercise/sports 3-5 days/week): RMR × 1.55
• Very active (hard exercise/sports 6-7 days a week): RMR × 1.725
• Extra active (very hard exercise/sports & physical job or 2x training): RMR × 1.9

7. Set your caloric intake goals: Depending on your weight goals, you can adjust your caloric intake to create a calorie deficit for weight loss or a surplus for weight gain. A general rule of thumb is that a deficit of 500-1000 calories per day will result in a weight loss of 1-2 pounds per week.

By following this step-by-step guide and understanding the Mifflin-St Jeor equation, you can calculate your caloric needs accurately. Remember to consult with a healthcare professional or registered dietitian to tailor your caloric intake and ensure it aligns with your individual needs and goals. Happy calculating!

A master guide to determining your caloric requirements using the Mifflin-St Jeor equation. The article “How to Calculate Your Caloric Needs” can be found on the MyFitnessPal Blog.