Calculating calorie requirements: The 4 best formulas – and why it’s worth knowing them

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Calculating calorie requirements. Want to calculate your calorie needs? Then this article is exactly what you are looking for. The 4 best formulas.

You might wonder if you need to calculate calories to lose weight or build muscle?

Certainly not. It’s a possible way.

The critical element is not the calories. It is one level above:

As long as you establish a feedback system and make goal-oriented decisions, counting calories is optional.

If you embrace the idea of calorie balance, become aware of portion sizes, and adjust them based on your weekly results, you’ll make progress.

But the calorie model is a weight loss feedback system that works very well for many people.

The idea behind the MBSC formula is that you have to calculate as little as possible.

Therefore, among the four solutions presented, you will find exactly what you need – whether you are the analytical type or not.

Why should you calculate your calorie needs?

There are always people who claim that calories don’t matter.

To believe that would be deceptive.

Of course, it’s true: A balanced diet is so much more than just calories.

The QUALITY of your food is extremely important.

When you get all the nutrients your body needs through a healthy diet, you will AUTOMATICALLY limit your calorie balance.

If you’re looking to change your physique—say, less fat and more muscle—then the “macros” and “micros” also come into play.

By the way, macros are carbohydrates, protein, and fat macronutrients.

And micros are the micronutrients, vitamins, minerals, and phytochemicals.

None of this changes the fact that you only break down fat when creating a calorie deficit.

And conversely, you only build muscle if you create a calorie surplus.

If you don’t use a feedback system, naked will look good for the lottery. How else would you know that your efforts are bearing fruit?

Knowing your calorie consumption, tracking your diet, and tracking your physique is an effective feedback system. A system that tells you objectively whether what you are doing is working.

You’ll learn things on the fly, so to speak – about your body, about your training, and about what you eat – that can help you stay slim for the rest of your life.

You can think of this method as a good pair of running shoes with which many people have had great results.

But to see if you like them, you should try them on for a while.

The next section covers the basics you should know before calculating your calorie consumption.

What influences your daily calorie consumption?

We recently discussed which six factors influence your daily calorie requirements.

Here is an overview of the qualitative factors (more details in the article ):

Basal Metabolic Rate (RMR)
Thermal Effect of Food (TEF)
Movement in everyday life (NEAT)
Strength Training (R)
Cardio Training (C)
Afterburn Effect (EPOC)

Today we go one step further: we talk about the quantity.

There are several ways to determine your calorie needs:

Measurement in the laboratory: In science, calorie consumption is usually measured directly in heat (calorimetry) or indirectly via the breath (spirometry). These methods are very precise but also very time-consuming.
Activity tracker: Most fitness bracelets try to calculate your effort expenditure (NEAT + R + C + EPOC) based on your movement profile – with very different results.

The more factors that go into the measurement, the more accurate the determined value is in most cases.

However, you can safely ignore most of the calorie information from activity trackers – they are simply too imprecise.

The Polar M430 sports watch seems to be an exception here. It should measure with similar accuracy as the SenseWear bracelet, which is unfortunately no longer available. In my experience, the Apple Watch also delivers usable values.

Approximation via formulas: Different formulas are based on statistical studies and approximate your calorie needs with varying degrees of accuracy. Values such as gender, body weight, age, body fat percentage, or height are usually considered. Some of these formulas work surprisingly well in practice.

This article discusses the third method – the formula approximating your calorie needs.

It is a proven method that I also use in coaching.

Calculating calorie requirements: The 4 best formulas – and how to use them

The formulas below will give you an idea of how much energy you need each day. They are part of the starting point from which you plan your flight route.

You should know that:

No formula, no matter how good, will give you values that are accurate to the decimal place.

The four methods presented here also vary in precision, as you will see.

But any formula is suitable for you to start with.

Therefore, you should choose a method you can now use to get off to a relaxed start.

And like this:

1. You calculate your calorie needs.

2. The result is the “baseline” for your calorie consumption.

3. Now, you plan your flight route. You can make adjustments at any time along the way.

Let’s start with the simplest formula.

Calculating calorie requirements #4 – The “rough house number” formula

Use this formula if you want a rough estimate (and math has never been a favorite subject).

They are considered: gender.

CALORIE REQUIREMENT FOR WEIGHT LOSS

Men: 2100-2500 kcal/day
Women: 1400-1800 kcal/day

CALORIE REQUIREMENT TO MAINTAIN WEIGHT

Men: 2700-2900 kcal/day
Women: 2000-2100 kcal/day

CALORIE REQUIREMENT FOR MUSCLE BUILDING

Men: 3100-3500 kcal/day
Women: 2300-2700 kcal/day

Calculating calorie requirements #3 – The “on the fly” formula

With this formula, you get a rough estimate that is quickly calculated.

I considered: body weight.

CALORIE REQUIREMENT FOR WEIGHT LOSS IN MEN

Men who do little exercise = body weight in kg x 22 kcal/kg
Men who are moderately active = body weight in kg x 24 kcal/kg
Men who move a lot = body weight in kg x 26 kcal/kg

Sample calculation for a man: 85 kg (body weight) x 22 kcal/kg (little exercise) = 1870 kcal per day to lose weight

CALORIE REQUIREMENT FOR WEIGHT LOSS IN WOMEN

Women who do little exercise = body weight in kg x 22 kcal/kg x 0.9
Women who exercise moderately = body weight in kg x 24 kcal/kg x 0.9
Women who move a lot = body weight in kg x 26 kcal/kg x 0.9

Sample calculation for a woman: 65 kg (body weight) x 22 kcal/kg (little exercise) x 0.9 = 1287 kcal per day to lose weight

You can use the same formula to determine your calorie needs if you want to maintain weight. The only difference is the kcal/kg factor.

Depending on how much you move, you do not take the factors 22, 24, and 26, as in the example above, but 31, 33, and 35:

CALORIE REQUIREMENT TO MAINTAIN WEIGHT

31, 33, or 35 kcal per kg body weight (depending on the intensity of movement in everyday life)

Sample calculation man: 75 kg (body weight) x 31 kcal/kg ( little exercise) = 2325 kcal per day to maintain the weight.

Sample calculation woman: 50 kg (body weight) x 35 kcal/kg ( a lot of exercise) x 0.9 = 1575 kcal per day to maintain the weight.

You can also use the formula to calculate your calorie needs to build muscle. Here you use the factors 40, 42, and 44:

CALORIE REQUIREMENT FOR MUSCLE BUILDING

40, 42, or 44 kcal per kg body weight (depending on the intensity of movement in everyday life)

Sample calculation man: 75 kg (body weight) x 42 kcal/kg ( moderate exercise) = 3150 kcal per day to build muscle.

Sample calculation for a woman: 50 kg (body weight) x 40 kcal/kg ( little exercise) x 0.9 = 1800 kcal per day to build muscle.

Calculating calorie requirements #2 – The Mifflin-St.Jeor Formula

Use this formula if you want to calculate your calorie consumption as accurately as possible but don’t know your body fat percentage.

There are different algorithms to calculate the basal metabolic rate. The Mifflin-St.Jeor formula is one of the newest and most accurate methods.

It takes into account: gender, height, age, and body weight.

STEP 1: CALCULATE THE BASAL METABOLIC RATE

Resting Metabolic Rate (RMR) is the amount of energy you need to keep your body’s vital functions running.

Males: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age) + 5

Females: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age) – 161

Example:

A woman who
29 years old and
is 170 cm tall and
weighs 60 kg,
has the following basal metabolic rate: RMR = 600 + 1062.5 – 145 – 161 = 1357 kcal/day.

STEP 2: DETERMINE THE ACTIVITY FACTOR

Choose the activity factor that best applies to you from the table below:

Activity level	Description	Factor
little active	Little or no exercise, mostly sedentary work	1.2
slightly active	light training / sport 1-3 days per week	1.375
moderately active	moderate exercise/exercise 3-5 days per week	1.55
very active	strenuous exercise/exercise 6-7 days per week	1.725
extremely active	strenuous daily training/sport, competitive sport, hard physical work, or 2x daily training	1.9

The activity factor includes ALL activities. So all the activities you spend your day doing, from getting up to going to bed (and maybe even after that): strength training, cardio, working, exercising, walking, housework, and everything else you do.

This also means you do not have to track calorie consumption during exercise. The activity factor fulfills this purpose.

Tip: If you’re trying to lose fat and are unsure which activity factor to use, go for the lower one. Most people overestimate their daily calorie expenditure and underestimate their daily energy consumption.

Therefore, it usually helps if you aim too low with the activity factor.

STEP 3: CALCULATE DAILY CALORIE NEEDS

Now that you know your BMR and activity factor, you can calculate your total daily calorie requirement (also known as Total Daily Energy Expenditure, or TDEE):

Calorie requirement = RMR × activity factor

Example (cont.):

We had already determined the woman’s RMR to be 1357 kcal/day.
Let’s assume she is moderately active (3-5x training per week).
Her activity factor is 1.55.

Then her calorie requirement = 1357 × 1.55 = 2103 kcal/day.

Calculating calorie requirements #1 – The Katch-McArdle Formula

Use this formula if you want to calculate your calorie needs as precisely as possible and know your body fat percentage in addition to your body weight.

The Katch-McArdle formula usually provides the most accurate values in practice because it is based on the weight of the most metabolically active lean body tissue.

Only older people should correct the result since the values are usually too high. Those who have passed 50 can correct the result by 5-10% downwards – or use the Mifflin-St.Jeor formula.

It takes into account: lean weight and body fat percentage.

STEP 1: CALCULATE THE BASAL METABOLIC RATE

Resting Metabolic Rate (RMR) is the amount of energy you need to keep your body’s vital functions running.

The Katch-McArdle formula applies to both men and women:

RMR = 370 + (21.6 × lean weight in kg)

Example:

A woman weighing 60 kg
with a body fat percentage of 20%
has a lean weight = 60 kg ×0.8 = 48 kg (80% of 60 kg).
So her basal metabolic rate is: RMR = 370 + (21.6 ×48) = 1407 kcal/day.

CARRY OUT STEPS 2-3 EXACTLY AS DESCRIBED UNDER “CALCULATE CALORIE REQUIREMENT #2”.

With the basal metabolic rate of 1407 kcal/day, the example of our 60 kg woman results in:

Her activity factor is 1.55.
Then her calorie needs = 1407 ×1.55 = 2181 kcal/day.

This is how it continues as soon as you know your calorie consumption.

Your calculated calorie consumption is your “baseline.” You start with that.

Once that’s done, you don’t need to constantly recalculate your calorie consumption.

The easiest way is to readjust your calorie intake based on your weekly progress.

To measure your progress, you need a feedback system. This also includes measuring your physique (weight, body fat percentage, photos, etc.) and maybe keeping a food diary.

Before you start, you should have a clear goal that excites you.

You can return to this article when you reach a milestone or bigger goal.

It’s also a good time to readjust the activity factor and recalculate your calorie consumption when you end a training phase (e.g., switch from losing fat to building muscle – or vice versa).

Now it depends on your goal: Do you want to lose weight or build muscle? (If you now say “both!”, read on here.)

Fat Loss: Create a deficit of about 10-30% of your total calorie needs. Women can be slightly more careful here (10 to 20%). Even if you already have a low body fat percentage, you should proceed more conservatively.

Building muscle: If you want to build muscle, you can aim for a calorie gain of around 10-30%. If you want to put on as little fat as possible, you should start with the lower value and make adjustments as you progress.

Congratulation! Now you have determined a starting value for your calorie goal.

You can find more help in this article.

Calculating calorie requirements – Conclusion

The four formulas presented will help you lose weight and build muscle if you want to calculate your calorie needs.

The Mifflin-StJeor and Katch-McArdle formulas provide the most precise values for the analytical among us.

Now you might be wondering: Do you need to calculate your calorie needs?

You must not. It’s just one possible way.

Your guarantee of success is not the calories alone, but that you establish a feedback system and make decisions based on your goal.

Calorie counting is such a weight loss feedback system.

Even if you don’t track calories, you should know the idea of calorie balance and take it seriously. For example, by being aware of portion sizes – perhaps using the snapshot method – and adjusting them based on your weekly results.

If you keep that in mind, you can expect the best progress.