BMR and TDEE Calculator – Online, Fast, and Free

Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) represents the minimum amount of energy the body requires to maintain vital functions at rest, such as breathing, blood circulation, and temperature regulation.

What is BMR used for?

• Estimation of daily energy requirements.
• Basis for nutritional calculations and dietary planning.
• Essential for adjusting diets for weight maintenance, loss, or gain.

How does the calculation work?

BMR calculation takes into account factors such as sex, age, weight, and height. The main formulas used are:

1. Harris-Benedict Formula (1919)

This is one of the most traditional formulas for estimating BMR:

For men:

$$ \text{TMB} = 88.362 + (13.397 \times \text{peso [kg]}) + (4.799 \times \text{altura [cm]}) - (5.677 \times \text{idade [anos]}) $$

For women:

$$ \text{TMB} = 447.593 + (9.247 \times \text{peso [kg]}) + (3.098 \times \text{altura [cm]}) - (4.330 \times \text{idade [anos]}) $$

2. Mifflin-St Jeor Formula (1990)

Currently considered one of the most accurate formulas for adults:

For men:

$$ \text{TMB} = (10 \times \text{peso [kg]}) + (6.25 \times \text{altura [cm]}) - (5 \times \text{idade [anos]}) + 5 $$

For women:

$$ \text{TMB} = (10 \times \text{peso [kg]}) + (6.25 \times \text{altura [cm]}) - (5 \times \text{idade [anos]}) - 161 $$

3. Schofield Formula (1985) – WHO

Recommended by the World Health Organization (WHO), especially for pediatric and elderly populations, with distinct age brackets:

For men:

• 0–3 years: BMR = 60.9 × weight – 54
• 3–10 years: BMR = 22.7 × weight + 495
• 10–18 years: BMR = 17.686 × weight + 658.2
• 18–30 years: BMR = 15.057 × weight + 692.2
• 30–61 years: BMR = 11.472 × weight + 873.1
• Over 61 years: BMR = 11.711 × weight + 587.7

For women:

• 0–3 years: BMR = 61.0 × weight – 51
• 3–10 years: BMR = 22.5 × weight + 499
• 10–18 years: BMR = 13.384 × weight + 692.6
• 18–30 years: BMR = 14.818 × weight + 486.6
• 30–61 years: BMR = 8.126 × weight + 845.6
• Over 61 years: BMR = 9.082 × weight + 658.5

Did you know?

• BMR accounts for approximately 60–75% of total daily caloric expenditure in sedentary individuals.
• Muscle is metabolically more active than fat, so individuals with greater muscle mass tend to have a higher BMR.
• Factors such as ambient temperature, health status, hormones, and genetics also influence BMR.

Important

Although these formulas are useful for estimating BMR, they do not replace clinical and metabolic evaluations performed by healthcare professionals.

Total Daily Energy Expenditure (TDEE)

Total Daily Energy Expenditure (TDEE) represents the total number of calories a person burns in a day, including calories needed to maintain vital functions, perform physical activities, and digest food.

What is TDEE used for?

Knowing your TDEE is essential for planning diets and training programs, as it indicates total daily energy expenditure and allows caloric intake to be adjusted for weight loss, gain, or maintenance.

How is TDEE calculated?

TDEE is calculated by multiplying Basal Metabolic Rate (BMR) by an activity level factor. BMR represents the energy expenditure required to maintain the body’s basic functions at rest.

The general formula is:

$$ \text{TDEE} = \text{TMB} \times \text{Fator de Atividade} $$

Methods for calculating TDEE

There are two primary methods for defining the activity factor:

Standard Method

Uses factors based on the intensity of daily activities:

• Sedentary: 1.2
• Lightly active: 1.375
• Moderately active: 1.55
• Very active: 1.725
• Extremely active: 1.9

WHO Method (World Health Organization)

The WHO recommends slightly higher multipliers to more accurately represent different levels of physical activity:

• Sedentary: 1.4
• Lightly active: 1.6
• Moderately active: 1.8
• Very active: 2.0
• Extremely active: 2.4

Thus, using the WHO method, the formula becomes:

$$ \text{TDEE}_{\mathrm{OMS}} = \text{TMB} \times \mathrm{NAF} $$

Practical example

For example, a person with a BMR of 1500 kcal who is moderately active would have a TDEE calculated as:

• Using the standard method: \( 1500 \times 1.55 = 2325 \) kcal/day
• Using the WHO method: \( 1500 \times 1.8 = 2700 \) kcal/day

Did you know?

• TDEE varies depending on age, sex, body composition, and physical activity level.
• Individuals with more muscle mass generally have a higher TDEE.
• Frequent and intense physical activity significantly increases TDEE.

Importance of TDEE in Nutrition

Understanding TDEE helps manage energy balance: consuming more calories than your TDEE leads to weight gain, while consuming fewer promotes weight loss.

Adjusting caloric intake based on TDEE is the foundation of effective and sustainable diets.

Final Considerations

TDEE calculation is an estimate and should be used as a guideline. For personalized nutrition plans, consulting a qualified professional is recommended.