Calculating How Many Calories You Need to Eat Daily to Lose Weight

In this post, we will explain how to calculate how many calories you should eat per day to lose weight so that you can organize your diet to shed those kilos effectively. We have also provided a daily calorie calculator below to simplify the process. But before, we find interesting to give you a brief explanation of different concepts related to calories.

Definition of calorie

A calorie is a heating unit which is defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius from 14.5 to 15.5 degrees at normal pressure.
A calorie is also used as a unit of measure of energy from ingested food and thus it is possible to develop appropriate low-calorie diets and allow weight reduction in the cases diagnosed obesity.
Calories are needed because they provide energy to the body to function properly. We have to maintain a balance between the calories we consume from food and calories we spend with our physical activity to prevent overweight and thinness.

Understanding food calorie

The energy of the food we eat is what allows us to perform daily activities. On food labels, information about the energy value of some foods is provided and is expressed in kcal/kg or in portions of 100 grams corresponding to a normal diet.
Proteins and carbohydrates provide 4 calories per gram and fats 9 calories per gram. To keep our weight, it is necessary to adjust consumption to our needs because what we consume in excess is stored as fat.
In a balanced diet, we should receive 55% of our energy from eating carbohydrates from fruits and vegetables that provide nutrients such as vitamins, minerals, and antioxidants and maintain alkaline balance of the pH of the body. Other sources of carbohydrates are bread, cereals, and legumes. Fats should not provide more than 35% of the total energy and are found in oils, butter, cream, and sausages. Plant and animal proteins should contribute about 15%.

How many calories should you eat daily for weight loss?

To find out your daily calorie requirements, you can use the Mifflin-St Jeor equation. It is actually the most accurate formula that calculates the number of calories you should eat in a day to maintain the Basal Metabolic Rate (energy needed to maintain body temperature and vital functions of our body), depending on age, sex, body weight, and height. This figure gives an estimation of how many calories you should eat to not gain or lose weight.

Step 1 – Calculate your BMR using the Mifflin-St Jeor equation

For men

BMR = (10 x Wt in kg) + (6.25 x Ht in cm) – (5 x age in years) + 5

For women

BMR = (10 x Wt in kg) + (6.25 x Ht in cm) – (5 x age in years) – 161

– Wt: Weight
– Ht: Height
Kg: Kilogram
Cm: Centimeter

As these equations use metric units, if you live in USA and UK, you will have to convert your weight and height from pounds and inches to kilograms and centimeters.

You get your weight in kilograms by dividing it in pounds by 2.2. [Wt (kg) = Wt (lbs) / 2.2]

You get your height in centimeters by multiplying it in pounds by 2.54. [Ht (cm) = Ht (inches) * 2.54]

Step 2- Calculate your Total Energy Expenditure (TEE)

Now that you have your BMR, the next step is to calculate your TEE. It is a number of calories you will burn per day considering your level of physical activity or exercise.

Sedentary life – no or very little exercise TEE = BMR x 1.2
Light exercise (1-3 days a week) TEE = BMR x 1.375
Moderate exercise (3-5 days a week) TEE = BMR x 1.55
Heavy exercise (6-7 days a week) TEE =BMR x 1.725
Very heavy exercise (2 times a day, very hard workouts) TEE = BMR x 1.9


If for example we consider a 28-year-old woman with 150 lbs, 71 inches tall and performing moderate exercise four days a week, the calories she should eat applying the formula would be:

Wt (kg) = 150 / 2.2 = 68 kg

ht (cm) = 71 * 2.54 = 180 cm

BMR = (10 x 68) + (6.25 x 180) – (5 x 28) – 161 = 1,504 calories

Applying the correct index of her moderate physical activity gives: 1,504 x 1.55 = 2,331 calories. This is an estimation of what she would have to eat per day to maintain her weight. If she exceeds that amount, she will gain weight. To lose weight, she has to eat less than 2,331 calories.

Simplify the process with our daily calorie calculator

To make it easier, you can use our calculator below. With our calculator, you do not need to convert your weight and height in metric units. Just input your data and our tool automatically does the conversion and calculation.

How much should you eat if you want to lose weight?

We are in the midst of a struggle between eating fewer calories to lose weight and that reduction of food does not undermine our daily requirements of vitamins, proteins, nutrients, minerals, fats, etc. The first thing to say is that you have to eat varied and healthy to have no major shortcomings. Drastic reduction in calories will produce quick weight loss, but this is not good for health. This strategy also appears ineffective in the long term to not be sustainable over time and cause the inevitable rebound effect regaining all the lost weight.

If you need 2331 calories and eat only 1500, you will go down in weight quickly, but the sacrifice will be enormous and may appear nutritional deficiencies. Lowering our caloric needs by 40% is a process that simply it does not work long term. When we reach our desired goal, we tend to compensate for the huge effort we have made eating so little, giving the deserved tributes. Our body metabolism will have fallen sharply, and when we return to eat as before, we regain what we lost just as fast.

The ideal is to lose weight slowly and steadily in the long term. We would recommend taking between 5% and 10% less of the calories you should take, of course following a varied and balanced diet. So using the above example, if 2331 calories are the number you get from the calculator, our advice is to consume about 2100 daily to reduce weight slowly and without excessive efforts that need to be offset by subsequent tributes. In this case, you can lose up to 2 lbs per month. Even if it is not much and not as fast as you want, you will never experience rapid weight loss side effects such as depression, stomach pain due to gallstones, loose skin. At all times, you have to be well nourished and fed with all kinds of healthy foods.

Calorie requirements are not static

Remember calories to keep your body without going up or lose weight is not a static number, as you drop pounds or you get older the number each time becomes smaller as because our caloric needs will be lower. On the other hand, exercising will increase your caloric needs, a good strategy to lose weight if you do not want to reduce the quantities of food, but should be continued in time if you want sustainable weight loss.

Exercises to consume calories

To decrease weight, it is advisable to practice aerobic exercises like brisk walking, jogging, stair climbing, swimming, squash, tennis, etc., because these help in developing the muscles and burning fat.
Exercises that burn more calories are cycling, rope jumping, swimming, aerobics, jogging or running.
Also important are the frequency and intensity of exercise. A person who jogs every day spends many more calories than someone who walks briskly every day or goes to the gym 3 times a week.