How to Calculate BMR and TDEE

If you’re trying to nail down your nutrition, you’re probably interested in finding out how many calories you need to be eating to achieve your fitness goals. Thats knowing how to calculate BMR and TDEE comes in.

Whether you want to lose weight or gain muscle, figuring out how much energy you use and adapting your diet accordingly is a must.

Nutrition can hold the key to success when it comes to transforming your body, and learning how to work out your BMR and TDEE is the first step to making your plans happen.

Read on for:

  • What is BMR?
  • What is TDEE?
  • How to calculate BMR
  • How many calories do I need?
  • The final word

Before you get started, you might be interested in keeping track of your body as you change your exercise routine and diet. Tracking progress is a fantastic way to stay motivated and continually improve. This BMI and weight scale from FitTrack is one of the most sophisticated ways to monitor the changes in your body, and you can even look at the data from your phone. Check it out.

Fittrack Scales

What is BMR?

Your BMR, or basal metabolic rate is the energy you expend if you do absolutely nothing. Imagine if you spent all day in bed doing nothing, we’re talking about that. The energy your body needs just to exist in a value of calories.

As you get older, you BMR decreases, which is what makes it harder to stay trim as you age.

Despite this, you should remember that by staying active, building muscle and hitting cardiovascular exercise on the regular, you can keep your basal metabolic rate at a good, high level.

You should also remember that it’s a bad idea to consume calories below your BMR regularly, otherwise your body could slip into starvation mode. This can actually lower your BMR further, which is counterproductive if your aim was to lose weight.

It’s important that everyone should know how to calculate BMR so they have a good idea of what they should be eating and how much they should be moving.

[Related Article: 5 Best Fat Burners for Women]

What is TDEE?

This is the actual amount of calories you spend in your normal day to day. It is based on your BMR, however the value of calories changes based on your activity levels.

If you’re hitting the gym every day or lead an active lifestyle, you’ll use more calories than if have a sedentary lifestyle. This is essentially you actual calorie usage.

By calculating your TDEE, you can alter your diet to suit your fitness of body goals. For example, if you want to lose weight you should reduce your TDEE value by no more than 20% to drop the pounds in a safe, healthy way and ensure you’re in a calories deficit.

If you want to gain weight, you can add an extra percentage to your TDEE, which will put you in a calorie surplus. This can be helpful if your goal is muscle or strength gains.

How to calculate BMR

woman calcuate BMR

Use the following formula to find the BMR for women:

BMR = 655 + (9.6 x weight in kg) + (1.8 x height in cm) – (4.7 x age in Yrs)

This will give you the value of how many calories you burn but just existing.

To calculate your TDEE you need to do the following: 

  • If you lead a sedentary life, with minimal activity and a desk job = BMR x 1.1
  • Light activity, where you play light sports 1-3 times a week = BMR x 1.275
  • Moderately active, where moderate level sports 3-5 times a week = BMR x 1.35
  • Hard activity, hitting the gym hard 3-5 times a week = BMR x 1.525

How many calories do I need?

Whatever your fitness goals, having the right nutrition behind you is essential. Whether you want to lose weight or gain muscle, having your calorie intake nailed down can mean the difference between success and failure.

Once you calculate BMR and TDEE, you can alter the numbers slightly to suit your goals. We’ve provided safe examples for both weight loss and weight gain.

Calories for weight loss:

To lose weight healthily and safely, we recommend you reduce your TDEE by about 15-20%[1]. Anything less than that could lead to health complications.

Weight loss = TDEE x 0.85-0.8 

Related article: Check out our favourite weight loss workouts right here.

Calories for weight gain: 

This will help you gain weight safely, without risking health. You may want to build strength and muscle, in which case you need to be in a calorie surplus of around 10-15%. If you are building muscle, this will allow for a lean bulk if your protein intake is correct.

Weight gain = TDEE x 1.1-1.15

Your maintenance weight is equivalent to your TDEE.

Build muscle in your lower body with the best legs workout for women

Final word – gymgirl hints and tips

Whatever your goals, it’s not just about calorie intake. To stay healthy as you head towards your ideal body composition, you need to be eating nutritious, wholesome food that nourishes your body. It is possible to lose weight or gain weight in a ‘dirty’ way, but if you opt for fast foods and simple sugars, you could experience some health issues.

You should also remember that, to gain or maintain muscle, you need to have enough protein fuelling your body. A great way to check you’re getting enough and to track your calorie and macro intake is to use the IIFYM diet. Check out our complete guide to try it for yourself.


  1. Davoodi SH, Ajami M, Ayatollahi SA, Dowlatshahi K, Javedan G, Pazoki-Toroudi HR. Calorie shifting diet versus calorie restriction diet: a comparative clinical trial study. Int J Prev Med. 2014;5(4):447-56.


gymgirlfit was created by health and fitness enthusiasts, with backgrounds in powerlifting and writing. We've written for a number of well-known fitness publishing companies.

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