RMR Calculator

Understanding Resting Metabolic Rate (RMR)

Resting Metabolic Rate (RMR) refers to the amount of energy or calories your body uses when it is in a complete state of rest. It considers the calories required for vital functions such as heart beating, respiration, and temperature regulation. RMR forms the foundation of your daily calorie needs, to which calories burned through physical activity and digestion are added.

Understanding your RMR is crucial for managing your weight and overall health. It helps in determining the number of calories you should consume to maintain, lose, or gain weight.

How We Calculate RMR

Our calculator uses the Harris-Benedict equation to estimate your Resting Metabolic Rate (RMR). This equation is widely used and considered reliable for most individuals. Here's how it works:

For men: RMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) - (6.755 × age in years)

For women: RMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) - (4.676 × age in years)

Let's look at two example calculations to better understand how this works:

Example 1: Adult Male

• Age: 39 years
• Height: 183 cm
• Weight: 95 kg
• Gender: Male

RMR = 66.5 + (13.75 × 95) + (5.003 × 183) - (6.755 × 39)
= 66.5 + 1306.25 + 915.549 - 263.445
= 2024.854 kcal/day
≈ 2025 kcal/day (rounded)

Example 2: Adult Female

• Age: 28 years
• Height: 165 cm
• Weight: 60 kg
• Gender: Female

RMR = 655.1 + (9.563 × 60) + (1.850 × 165) - (4.676 × 28)
= 655.1 + 573.78 + 305.25 - 130.928
= 1403.202 kcal/day
≈ 1403 kcal/day (rounded)

After calculating the base RMR, we then estimate daily calorie needs for different activity levels by multiplying the RMR by an activity factor:

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

Factors Affecting RMR

Several factors can influence your RMR:

• Age: RMR typically decreases with age
• Gender: Men generally have a higher RMR than women
• Body composition: More muscle mass increases RMR
• Genetics: Some people naturally have a higher or lower RMR
• Hormones: Thyroid hormones, for example, can affect RMR
• Diet: Severe calorie restriction can lower RMR
• Environmental temperature: Extreme cold or heat can increase RMR
• Fasting/Dieting: RMR can decrease if a person is dieting or fasting because the body conserves energy during these periods

How to Increase Your RMR

While your RMR is influenced by factors you can't control (like age and genetics), there are ways to potentially increase it:

• Increase muscle mass: Engage in resistance or strength training exercises
• Eat regular meals: Eating regularly can prevent metabolic slowdowns
• Stay hydrated: Drinking water can temporarily boost metabolism
• High-Intensity Interval Training (HIIT): This type of exercise can boost metabolism

Remember, consistency is key in muscle building, and it's important to allow your muscles time to rest and recover between workouts.

Using Your RMR Results

Once you know your RMR, you can use it to:

• Set realistic weight loss or gain goals
• Create an effective meal plan
• Understand how many calories you need for different activity levels
• Make informed decisions about your diet and exercise routine

Remember, RMR is just one part of the equation. To maintain weight, you need to consume the same number of calories as you burn through RMR, physical activity, and the thermic effect of food. To lose weight, you need to create a calorie deficit, and to gain weight, a calorie surplus.

How to Use This Calculator

1. Enter your age in years
2. Select your gender
3. Enter your height (you can choose between cm, feet, or inches)
4. Enter your weight (you can choose between kg or lbs)
5. Click the Calculate RMR button
6. Review your results, including your RMR and daily calorie needs for different activity levels

Remember, while this calculator provides a good estimate, individual RMR can vary. For the most accurate measurement, consider professional testing methods like indirect calorimetry.

FAQ

Research References

• Mifflin MD, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990
• Harris JA, Benedict FG. A Biometric Study of Human Basal Metabolism. Proc Natl Acad Sci U S A. 1918

Parameter Details

• Age: Your current age in years.
• Gender: Biological sex, affects RMR calculations.
• Height: Your height (54.6 cm - 272 cm).
• Weight: Your current weight (20 kg - 635 kg).