Weight Loss Calculator

“How many calories do I have to eat to lose weight?”

“I’ve been tracking my calories in and calories out but I am not losing weight, what should I do?”

These are some of the questions I am frequently asked by my clients.

When it comes to weight loss and more specifically fat loss, calories are not the only thing that matters but they are certainly the most important. Therefore, it is crucial to have a better understanding of how many calories we should be consuming.

Calories are units of energy and they refer to the energy that can be extracted from nutrients (food) we consume. To be precise, calories are units of heat measurement.

A mistake we tend to make is to think of calories as an abstract concept, while on the other hand they refer to energy, something measurable. 

 

1g Fat: 9kcal

1g Carb: 4kcal

1g Protein: 4kcal

1g Alcohol: 7kcal

 

The first thing to do is to find your “Total Daily Energy Expenditure” (TDEE).

The formulas to calculate TDEE are mainly used with people who are overweight, therefore, if you are short and slim these formulas might underestimate your daily calorie intake. Further, these formulas have a percentage of error and you must test the results on yourself and adapt it accordingly.

Formula 1

Man

Basal Metabolic Rate (BMR) correspond to 1kcal/(kg*h)

 A man that weights 80kg:

BMR = 1kcal/(kg*h) x 80kg x 24h = 1920kcal

We will add 30% to this (10% Thermic Effect of Food and 20% Exercise Activity) to find the TDEE.

1920kcal + (1920 x 30%kcal) = 2496kcal

The formula above is good for a man with a sedentary job and that trains 3 times a week.

Woman

Basal Metabolic Rate (BMR) correspond to 0,9kcal/(kg*h)

A woman that weights 55kg

BMR = 0,9kcal/(kg*h) x 55kg x 24h = 1188kcal

We will add 30% to this (10% Thermic Effect of Food and 20% Exercise Activity) to find the TDEE.

1188 kcal + (1188 x 30%kcal) = 1544kcal

 

Formula 2

The Harris–Benedict equation (also called the Harris-Benedict principle) is a method used to estimate an individual's BMR.

The estimated BMR value may be multiplied by a number that corresponds to the individual's activity level; the resulting number is the approximate TDEE.

First we find the BMR.

Man

BMR= 66.5+(13.75 × weight in kg)+(5.003 × height in cm)–(6.755 × age/years)=Kcal

Woman

BMR = 655.1 + (9.563 ×weight in kg)+( 1.850 × height in cm)– (4.68×age/years )

 

The BMR result may be multiplied by a factor that approximates an individual's physical activity level to estimate their TDEE. The following table enables approximation of an individual's daily TDEE based on some example lifestyles. 

 

 

Example: a 30 year old man that weights 80kg man, 180cm tall and works as a construction worker.

 

BMR= 66,5 + 13,75 x 80 =5,003 x 180 – 6,775 x 30 = 1864 kcal 

Now we multiply that number for 1.76 

1864 x 1.76 = 3280kcal

 

Once we have found our TDEE using the formulas above, how many calories do we need consume in order to lose weight? Generally speaking, a deficit of about 10 to 25 % works best for most people.

A light caloric deficit combined with the right training will lead you slowly towards a better body composition. 

Feel free to use either one of the weight loss calculators above and find out how many calories you should be eating. 

Track your weight every other week and work out your monthly average before changing and adjusting the formulas.

Also, very important is to make sure that the diet you follow is sustainable. Your diet must accommodate your social life and provide psychological and emotional well-being, while still progressing towards your goals.