Calculate calorie needs

Geschatte leestijd: 6 minuten When you want to lose weight or gain weight, it is important to first determine your daily calorie needs. After all, if you want to lose weight, you need to eat fewer calories than your daily calorie needs, and if you want to gain weight, you need to eat more calories. These are respectively called a negative and a positive energy balance.

Calculating Caloric Needs in Kcal

To determine how many calories you need daily and how much you should eat to lose or gain weight, you need to consider six different factors. These 6 factors influence your daily caloric needs. These 6 factors are:

1. Basal metabolic rate, also known as Basal Metabolic Rate (BMR)
2. Activity level
3. Body weight
4. Lean body mass (LBM)
5. Age
6. Gender

Also read our article: how many calories am I allowed per day?

Basal Metabolic Rate (BMR)

Your BMR is the number of calories your body burns to perform normal bodily functions, including blood circulation, temperature regulation, digestion, and any other metabolic processes in your body. Your BMR does not include physical activity in the calculation. Your BMR accounts for the largest portion of your daily calorie needs, about two-thirds to 80 percent of the total. BMR varies greatly from person to person, depending on genetic factors.

Activity Level

In addition to your BMR, your activity level is the second largest factor influencing your daily caloric needs. The more active you are, the more calories you burn.

Body Weight

Your total body weight and your total body size also strongly influence your caloric needs. The larger you are, the more you need to move.

Lean Body Mass (LBM)

Your total body weight affects your caloric needs, but when you divide that weight into fat mass and lean mass, you can calculate the caloric needs more accurately. The more lean mass (Lean Body Mass, LBM) you have, the higher your BMR. This also means that when you build more muscle mass, you burn more calories, even at rest. Muscle mass requires a lot of energy to maintain itself. So, the best way to increase your BMR is by increasing your LBM. Weight training helps – indirectly – to burn body fat.

Age

Your age also affects your caloric needs. As you get older, your metabolism slows down and you burn fewer calories. However, if you are active, you can largely counteract this decrease in metabolism through weight training and good nutrition!

Gender

Men usually need more calories to function than women. On average, a man needs 2800 calories per day compared to 2000 for women. This is not so much related to gender differences, but more to the way the body is built. Men on average have much more muscle mass than the average woman, so they also need more calories to burn.

How Many Calories Do I Need?

There are many formulas to calculate how many calories you need daily, taking into account these six factors. When your LBM is included in the calculation, it will always be more accurate. However, you can already get a reasonable estimate by using only your body weight as a starting point: the ‘quick’ method.

Calculating Caloric Needs: Quick Method

The quick method only uses your total body weight for the calculation. It does not consider whether you have 100 kg of muscle or 100 kg of fat. The calculation estimates your lean mass based on averages and can therefore vary considerably if you have above-average muscle or fat mass. The calculation is as follows:

BMR = (body weight in kg / 0.45359237) * 15 – 16 calories Fat loss = (body weight in kg / 0.45359237) * 12 – 13 calories Weight gain = (body weight in kg / 0.45359237) * 18 – 20 calories (the weight is divided by 0.45359237 to convert kilograms to pounds)

The calculator below assumes 13 calories per kilogram of body weight for losing weight, 16 calories for BMR, and 20 calories for gaining weight. Enter your weight and click: Calculate BMR. If you want to enter numbers after the decimal point, use a period (.) instead of a comma, otherwise the calculator will not work.

• Weight (kg)
• Lose weight
• Maintenance
• Gain weight

As mentioned, this method is very inaccurate. You will quickly end up too high. The quick method is actually only suitable for someone with a normal percentage of body fat. If you want to work more accurately, the Harris-Benedict Formula is very suitable.

Harris-Benedict Formula

The Harris-Benedict formula uses your weight, gender, height, and age to calculate your BMR. The only thing not included is your LBM. The advantage of this is that you don’t need to have your body fat measured. This calculation also estimates your lean mass based on averages. Because height, gender, and age are known, these averages can come closer to your personal needs. Even now, this may deviate if you have above-average muscle or fat mass for your age, height, and gender. However, this deviation will be smaller than with the quick method shown above.

The calculation is as follows: Men: BMR= 66 + (13.7 * weight in kilograms) + (5 x height in cm) – (6.8 x age in years) Women: BMR= 655 + (9.6 * weight in kilograms) + (1.8 x height in cm) – (4.7 x age in years)

With the help of the following activity levels, your maintenance calorie needs can be calculated, i.e., how much you should eat with your BMR and your activity level to neither gain nor lose weight.

1. Little or no training, office work — x 1.2
2. Light training/sports 1-3 days per week — x 1.375
3. Average training/sports 3-5 days per week — x 1.55
4. Heavy training/sports 6-7 days per week — x 1.725
5. Heavy daily training/sports plus physical work or training twice a day, marathon, football camp, competition, etc. — x 1.9

In the calculator below, you need to enter your weight, your height, your age, and the number of your activity level. Then click on the BMR button that corresponds to your gender. If you want to enter numbers after the decimal point, use a period (.) instead of a comma, otherwise the calculator will not work.

• Weight (kg)
• Height (cm)
• Age
• Activity Level 12345
• Your BMR
• Maintenance

Katch-McArdle Formula

If you want to know even more accurately what your BMR is, you need to include the LBM in the calculation. This is done in the Katch-McArdle Formula. This is the formula coaches in our app can use to calculate the needs for their clients. Therefore, keep a close eye on the effect on your weight when you base your intake on a calculated need. For example, if you have been eating at your calculated need for a few weeks and you gain weight, or if you lose weight, then your calculated need was apparently off. This way, you can assess for yourself whether you need to increase or decrease your calculated need. The Katch-McArdle formula does not distinguish between men and women. Why not? Very simple: the difference between men and women lies in the difference in muscle mass. If you know that muscle mass (LBM), then no further distinction is needed in the calculation! Fat does not burn calories, so the calculation is based solely on your muscle mass. Your LBM is calculated based on your weight and your body fat percentage. Of course, you need to know that body fat percentage! How do you get that? Your body fat percentage is best measured with a skinfold caliper. Measuring body fat percentage with a skinfold caliper remains the most reliable form of body fat measurement. The Katch-McArdle formula is as follows:

BMR = 370 +(21.6 * LBM in kg)

With this formula, your maintenance calorie needs can also be calculated. Use the list of activity levels from the Harris-Benedict formula for that purpose. In the calculator below, you need to enter your weight, your body fat percentage, and the number of your activity level (see above), then click on Calculate BMR. If you want to enter numbers after the decimal point, use a period (.) instead of a comma, otherwise the calculator will not work.

• Weight (kg)
• Fat % (cm)
• Activity Level 12345
• Your LBM (kg)
• Your BMR
• Maintenance

You cannot make the calculation more precise yourself. Only in a laboratory can you go further, but that is not necessary at all. With the data you now have, you can make a fairly accurate estimate of the amount of calories you need to lose or gain weight. To start with, you can take the maintenance level and add 500 calories to it (gaining weight) or subtract it (losing weight).

It remains an estimation!

However, all formulas are estimates. More importantly, people are quickly inclined to fill in the activity level incorrectly, even with the best intentions. It is simply difficult to determine exactly which activity level suits you. Also, this does not have to be the same every week. Therefore, keep a close eye on the effect on your weight when you base your intake on a calculated need. For example, if you have been eating at your calculated need for a few weeks and you gain weight, or if you lose weight, then your calculated need was apparently off. This way, you can assess for yourself whether you need to increase or decrease your calculated need.