BMR and TDEE Calculator
Calculate your daily caloric needs based on both Mifflin-St Jeor and Harris-Benedict formulas. The calculator takes into account your gender, age, weight, height, and physical activity level.
The information provided on this page is for reference only. The calorie calculator results are for informational purposes only and should not be used as a basis for self-treatment.
Understanding Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE)
Maintaining a healthy body weight or pursuing specific fitness goals requires a solid understanding of your body's energy requirements. Two important concepts in this context are Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). These values help estimate how many calories your body needs at rest and throughout the day, and they play a key role in creating effective nutrition and exercise plans.
What Is Basal Metabolic Rate (BMR)?
BMR refers to the number of calories your body needs to maintain basic physiological functions while at rest. These include breathing, circulation, cell production, and temperature regulation. BMR accounts for about 60–70% of your total daily energy expenditure.
How to Calculate BMR
There are several methods for estimating BMR, but two of the most well-known are:
1. Mifflin-St Jeor Formula (1990)
This equation is widely considered to be more accurate, especially for modern lifestyles and body compositions:
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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
This formula was introduced in a study by Mifflin et al. in 1990 and has been supported by multiple reviews as one of the most accurate for predicting resting energy expenditure in healthy adults (Mifflin et al., 1990).
2. Harris-Benedict Formula (1919)
One of the earliest methods developed to estimate BMR:
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For men:
BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) – (6.755 × age in years) -
For women:
BMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) – (4.676 × age in years)
Although historically significant, this formula tends to overestimate BMR in modern populations due to changes in average body composition since the early 20th century (Frankenfield et al., 1998).
What Is Total Daily Energy Expenditure (TDEE)?
TDEE is the total number of calories you burn in a day, including:
- BMR (basic bodily functions)
- Physical activity (exercise and daily movement)
- Thermic Effect of Food (TEF) – energy used for digestion
- Non-Exercise Activity Thermogenesis (NEAT) – spontaneous movements, posture, fidgeting, etc.
To calculate TDEE, you first determine your BMR and then multiply it by an activity factor:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little to no exercise | 1.2 |
| Lightly active | Light exercise/sports 1–3 days/week | 1.375 |
| Moderately active | Moderate exercise/sports 3–5 days/week | 1.55 |
| Very active | Hard exercise/sports 6–7 days/week | 1.725 |
| Extra active | Very hard training/job (e.g., athlete, laborer) | 1.9 |
TDEE = BMR × Activity Level Multiplier
Which Formula Should You Use?
While both methods are still in use, the Mifflin-St Jeor Formula is generally recommended for most individuals due to its greater accuracy across a broader range of body types and its validation in more recent studies.
According to a systematic review by Frankenfield et al. (2005), the Mifflin-St Jeor equation had the highest accuracy among commonly used predictive equations for resting metabolic rate, especially for non-obese and obese adults alike.
Final Thoughts
Knowing your BMR and TDEE helps you make informed decisions about your calorie intake, whether your goal is weight loss, maintenance, or muscle gain. Among the two main formulas, the Mifflin-St Jeor equation is typically the better choice for modern users, backed by stronger scientific validation and better alignment with contemporary body metrics.
References
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Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO.
A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–7. doi: 10.1093/ajcn/51.2.241 -
Frankenfield D, Muth E, Rowe W.
The Harris-Benedict Studies of Human Basal Metabolism: History and Limitations. J Am Diet Assoc. 1998;98(4):439–45. doi: 10.1016/S0002-8223(98)00100-X -
Frankenfield D, Roth-Yousey L, Compher C.
Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–89. doi: 10.1016/j.jada.2005.02.005