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What is BMR and TDEE?

TDEE and BMR calculator

Maintaining a healthy body weight is a goal shared by many individuals, if you’re one of them, you may want to know ‘what is BMR and TDEE?’

When losing weight, it is very useful to have at least a basic understanding of two important concepts: Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Here, we will delve into what BMR and TDEE are, how to calculate them, and how they can be utilised for weight management.

What is BMR and TDEE?

BMR, or Basal Metabolic Rate, is the number of calories your body needs to function at rest, this is used during basic functioning such as breathing, circulating blood, and regulating body temperature.

TDEE, or Total Daily Energy Expenditure, encompasses the total number of calories your body burns in a day, accounting for physical activity and exercise and the basal metabolic rate.

How to Calculate BMR and TDEE

In order to estimate your BMR and TDEE as accurately as possible, you need to consider various factors, such as:

  • Age

  • Sex

  • Height

  • Weight

  • Activity level

That being said, several formulas exist when calculating BMR and TDEE, so understandably it gets a little confusing if you’re not familiar with it. Not to worry, we’re here to help!

TDEE calculator

How to Work Out Your BMR

Now that you’re aware of the BMR definition, you can see below how to use the most common formula to work out your BMR according to your sex.

One widely used formula to calculate BMR is the Harris-Benedict Equation (you may also see names such as Revised benedict equation too!). This formula takes into account factors such as gender, weight, height, and age to estimate your BMR and the formulas for men and women are different:

Here are the formulas to work out your BMR each men and women

For Men:

BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years)

For Women:

BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age in years)

How to Work Out Your TDEE

You may have used a TDEE calculator (UK) before, but you may notice that before you use that you need to have your BMR since this is the staple part of the TDEE equation.

Simply put, once you have calculated your BMR, you can determine your TDEE by multiplying your BMR by an activity factor.

The activity factor corresponds to your daily physical activity level, and this is often encapsulated within 5 different activity factors, these are the common factors you’ll see most often:

  1. Sedentary (little to no exercise): TDEE = BMR x 1.2

  2. Lightly active (light exercise/sports 1-3 days/week): TDEE = BMR x 1.375

  3. Moderately active (moderate exercise/sports 3-5 days/week): TDEE = BMR x 1.55

  4. Very active (hard exercise/sports 6-7 days a week): TDEE = BMR x 1.725

  5. Extra active (very hard exercise/sports and a physical job): TDEE = BMR x 1.9

what is BMR

What are the Types of TDEE Equations?

BMR, TDEE, it seems pretty straight forward, although apart from the Harris-Benedict Equation, there are a few other equations commonly used to estimate TDEE too.

These equations take into account additional factors such as lean body mass and body fat percentage; let's explore a couple of them:

The Mifflin-St Jeor Equation

This equation is considered more accurate for estimating TDEE as it takes into account contributing factors to your total daily expenditure that maybe would have gone overlooked in the traditional formula.

For example, sex is a huge player in how much expenditure fluctuates, and this is why for this formular there are separate equations for men and women.

Men TDEE Formula: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5.

Women TDEE Formula: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161.

Katch-McArdle Equation

This equation for TDEE is particularly useful for individuals who have accurate metrics and want to use the TDEE calculator to utilise their body fat measurements.

Arguably, this is another way to make it even more accurate, but do note that if you’re going to use body fat measurements then you should ensure that said measurements are accurate; the best way to do this is by using the right tools like a body fat measurement calliper for instance.

Nonetheless, if you have these measurements and are confident in them, the formula is as follows:

TDEE = BMR x (1 - (body fat percentage / 100)

Using TDEE to Lose Weight

Once you have determined your TDEE, it can serve as a valuable tool for weight management. To lose weight, you need to create a calorie deficit, which means consuming fewer calories than you burn, what you burn being your TDEE.

By reducing your calorie intake moderately, you can aim to lose 1-2 pounds (0.5-1 kg) per week. It is important to prioritise a balanced and nutritious diet while maintaining a sustainable calorie deficit and not being over restrictive.

Any kind of overly restrictive diet increases the risk of not only fluctuations in your metabolism but also builds a bad relationship with food.

Using TDEE to Gain Weight

On the other hand, if your goal is to gain weight, you need to create a calorie surplus by consuming more calories than your TDEE.

Aim to increase your calorie intake gradually, typically by 250-500 calories per day, to promote healthy weight gain. Focus on consuming nutrient-dense foods that provide the necessary macronutrients (carbohydrates, proteins, and fats) and micronutrients (vitamins and minerals) for your body's needs.

Using BMR to Lose Weight

While TDEE takes into account physical activity, BMR can also be used as a starting point which is why you can calculate BMR for weight loss too.

So, you need a BMR calculator for a calorie deficit.

Simply put, by consuming fewer calories than your BMR, you can create a calorie deficit. However, it is essential to consult with a healthcare professional to ensure that your calorie intake remains within a safe and healthy range.

Using BMR to Gain Weight

You know how to lose weight using BMR, but if your goal is to gain weight, you can use your BMR as a starting point to calculate your calorie needs.

By consuming more calories than your BMR, combined with a structured exercise program, you can promote muscle growth and healthy weight gain.

what is TDEE

Incorporating TDEE and BMR into Your Routine

So while you know how to calculate BMR and TDEE, to effectively utilise them for weight management it is crucial to monitor your progress and make adjustments as necessary.

Keep in mind that these calculations provide estimates, and individual variations exist. Regularly reassessing your TDEE and adjusting your calorie intake accordingly can help you stay on track and achieve your goals.

Remember, achieving and maintaining a healthy weight is a multifaceted journey that goes beyond simple calorie calculations. Other factors such as overall dietary quality, physical activity, sleep, stress management, and individual differences should also be considered for long-term success.

Now, all of the words that were flying around such as maintenance calories, TDEE, BMR all begin to make more sense which is great, but don’t forget that there can be many other factors that contribute to your weight management.

Nonetheless, this is still a great starting point.

Before You Go…

Understanding your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) can be immensely beneficial for weight management.

By calculating these values and tailoring your calorie intake accordingly, you can understand your food better and start eating more mindfully.

However, it is essential to approach weight management holistically, considering various lifestyle factors and seeking professional guidance when needed. Utilise BMR and TDEE as tools to support your overall health and well-being on your journey towards a balanced and sustainable lifestyle.

Don’t forget, if you need help with weight management, nutrition and exercise, talk to us at Infinity Performance to see how we can help.


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