You've decided to build muscle, but do you really know how many calories you should be consuming every day to reach that goal?
Calculating your caloric needs may seem complex, but it's actually a crucial step in transforming your body. Whether you're male or female, sedentary or sporty, understanding your basal metabolic rate and daily calorie expenditure is essential.
To help you calculate your basic needs, we'll be using recognized formulas such as Black et al.
By learning to calculate your calorie, protein, carbohydrate and fat requirements, you'll not only be able to build muscle mass efficiently, but also know when to eat to build mass.
Caloric and macronutrient requirements calculator
Recommended macronutrient breakdown (approx.)
Contents
How do you define your basal metabolic rate?
Before diving into the calculations, let's understand what basic metabolism is. It's the minimum amount of energy our body needs to function at rest.
Knowing your basal metabolic rate is important for adjusting your calorie intake accordingly, either to gain mass or to lose weight.
Calculation of basal metabolic rate (BMR)
There are several formulas for calculating basal metabolic rate, but one of the most widely used is the Black et al. equation, which takes into account age, sex, height and weight.
Here are the formulas:
Gender | Formula |
Men | Kcal = [0.963 x Weight(kg)0.48 x Height(m)0.50 x Age(yr)-0.13] x (1000/4.1855) |
Woman | Kcal = [1.083 x Weight(kg)0.48 x Height(m)0.50 x Age(yr)-0.13] x (1000/4.1855) |
Please note: these formulas provide an estimate of your basal metabolic rate. But beware: each metabolism is unique, and this data will only be a more or less accurate indication.

Factors influencing basal metabolic rate
Several factors can influence basal metabolic rate beyond age, gender, height and weight.
Level of physical training, body composition (muscle mass vs. fat mass) and even certain hormonal aspects play a role.
Here is a list of the main factors:
- Level of physical activity
- Proportion of muscle mass
- Hormonal factors (e.g. thyroid function)
- Temperature and climate
- Global health and drug treatments
- Genetics
Once you've defined your basal metabolic rate, it's important to understand that this theoretical intake requirement doesn't take into account the expenditure associated with your physical activity.
Add physical activity needs
Physical activity is a crucial factor in calculating calorie requirements. It is not limited to the duration of exercise, but encompasses its intensity and frequency. Understanding this helps to fine-tune the diet according to activities and objectives.
Evaluate the intensity and frequency of weight training activities
The intensity of physical activity varies greatly: light walking, intense running, strength training. Assessing this intensity, combined with the frequency of training, is essential in determining the additional energy required.
Here is a table showing the energy expenditure involved in practising a number of sports:
Sport | Energy expenditure (kcal/hour) | Sport | Energy expenditure (kcal/hour) |
---|---|---|---|
Volleyball | 250 | Tennis, singles | 450 |
Basketball, soccer | 570 | Judo | 750 |
Crawl | 750 | Squash | 900 |
Running (12 km/h) | 900 | Yoga | 300 |
Pilate | 230 | Zumba | 430 |
Tai chi | 200 | CrossFit | 700 |
Stretching | 140 | Climbing | 650 |
Dance | 430 | Martial arts | 500 |
Golf | 350 | Tennis | 450 |
Badminton | 550 | Bowling | 200 |
Ping pong | 250 | Padel | 550 |
Gymnastics | 340 | Jumping jacks | 600 |
HIIT | 800 | Piloxing | 800 |
Spiining | 700 | Floor bar | 250 |
STEP | 700 | Body pump | 540 |
Please note: these figures are indicative and may vary greatly depending on the individual, intensity and level of training...
By adding these sports-related values to the basal metabolic rate, we obtain the theoretical value of the number of calories required by the body to function and maintain itself.
Very schematically, with a higher intake we gain weight and, conversely, if we don't reach this intake, the body will draw on reserves and we will lose weight.
Integrating individual variables
Let's not forget that each individual is unique, and this uniqueness is reflected in our nutritional requirements. As we have seen in the calculation formulas, age, sex and body size have a considerable influence on our caloric requirements.
Our lifestyle and activities of daily living (e.g. physical work) also need to be taken into account. Understanding and integrating these variables is important for a personalized and effective nutritional plan.
Adjustments to specific objectives
Personal goals - weight loss, mass gain, maintenance - dictate the calorie adjustments required. It's essential to adjust calorie intake regularly to reflect progress and changes in eating habits.
When it comes to building mass, we rarely bother to calculate our basic metabolism, and then the associated expenditure. In general, we aim to reach 45 to 55 kcal/kg/d. This intake, over several months, is recognized as effective for most athletes.
For simplicity's sake, here's a fitting table:
Objective, | Recommended fit |
Lose weight | Reduce basic calories by 300 to 500 kcal compared to requirements |
Weight gain | Achieve 45 to 55 kcal/kg/d |
Maintenance | Staying close to the required input |
Caution: These adjustments must be made with caution and according to individual body responses to this new type of diet.

Adjusting your needs according to your morphotype
Morphotypes refer to the different categories of human body, generally classified into three types: ectomorph, mesomorph and endomorph.
Ectomorphs are naturally slim and have difficulty gaining weight; mesomorphs gain muscle mass easily and have an average body structure; endomorphs tend to store more fat and have a slower metabolism.
Recognizing your body type is important, as it influences your diet and training program.
For example, an ectomorph may require a higher calorie intake for mass gain, while an endomorph should focus on a more balanced diet to avoid excessive fat gain.
How can I easily identify my morphotype?
To determine your morphotype, it's important to consider factors such as ease of weight gain or loss, body fat distribution, and general morphology.
A simple method is to observe physical characteristics: ectomorphs generally have long limbs and little body fat, mesomorphs have average bone structure and a natural ability to build muscle, and endomorphs often have a rounder body and a tendency to store fat.
Another easy and basic technique for estimating your morphotype is to measure the circumference of your wrist using your thumb and forefinger.
- If you can't get the two fingers to meet around your wrist, this indicates an endomorphic morphotype.
- If your fingers meet but don't overlap, this suggests a mesomorphic morphotype.
- Finally, if the index finger covers the thumbnail, this indicates an ectomorphic morphotype.
In addition, more specific tests, such as skinfold measurement or bioimpedancemetry, can help refine this classification.
What's the best approach for each body type?
- Ectomorph: Ectomorph individuals gaining mass should aim for a higher-than-normal calorie intake, with a macronutrient distribution favoring carbohydrates and protein to stimulate muscle growth. They can benefit from frequent meals with calorie- and nutrient-rich foods.
- Mesomorph: Mesomorphs can follow a more balanced diet, with an even distribution of macronutrients. A caloric intake slightly in excess of their maintenance requirements may be sufficient for effective mass gain.
- Endomorph: Endomorphs need to be careful with their calorie intake, favoring low-energy-density foods and controlling their carbohydrate intake. A slight caloric surplus with careful attention to food quality is recommended.
How do you plan your diet and choose macronutrients?
Dietary planning is as much a pillar of mass gain as training itself. It's essential to choose your nutrients wisely: proteins, carbohydrates and fats, as well as the timing of their intake.
Ideal macronutrient distribution for mass gain
For effective mass gain, the macronutrient balance must be meticulously adjusted. In general, a distribution of 20/25% protein, 50-55% carbohydrates and 25-30% fat is recommended. This distribution may vary according to individual responses and specific objectives.
Example for an 80 kg athlete, during a period of mass gain
To meet the 50 kcal/kg/d target, we aim to reach 4000 kcal. There is also a requirement for 2 g protein/kg, i.e. 160 g protein. To meet these requirements, we can propose a balanced daily intake of 160 g protein, 400 g carbohydrates and 200 g fat.
To help you, here's a free protein needs calculator and a macronutrient breakdown chart:
Macronutrients | Recommended percentages |
Protein | 20-25 % |
Carbohydrates | 50-55 % |
Lipids | 25-30% |
Please note: percentages should be adjusted according to individual needs and reactions.
Examples of foods and meals to cover your caloric needs
Choosing the right foods is crucial to healthy, effective weight gain. Protein-rich foods such as lean meat, fish, eggs and legumes are essential. Complex carbohydrates (oats, brown rice, quinoa...) and healthy fats (avocado, oils, nuts, butter in reasonable quantities...) are crucial.
Whey and gainers are very interesting for easily supplementing intakes. But beware of their composition, origin and manufacturing methods.
As far as possible, choose additive-free products made fromraw, organic ingredients, to supplement your diet in a healthy way, without damaging your health in the long term.
Here are some examples of meals:
- Breakfast: omelette (organic or free-range eggs) with vegetables and oat flakes
- Lunch: organic (or free-range) grilled chicken, quinoa and green salad
- Dinner: baked trout (local French farm), sweet potatoes and grilled vegetables
- Snack(s) or replacement of animal protein intake: whey without additives and/or mass gainer without additives.
You need to vary the sources of each macronutrient, and make sure you eat them at the right times to guarantee a balanced daily intake of nutrients. And be sure to choose quality ingredients, with strict production and manufacturing standards.
Monitoring and adjusting caloric requirements
Monitoring and adjusting caloric requirements are key steps in successful weight gain. This involves listening carefully to your body and continuously adapting your diet and training.
Techniques for monitoring changes in body mass
There are a number of methods you can use to monitor your body mass. Scales and tape measures are classic tools for measuring body weight and circumference.
However, you can also take into account body composition (muscle mass vs. fat mass) through more precise analyses such as bioimpedance. In this case, be careful not to place too much importance on it, as these devices are not always very accurate, and measurements should be taken with caution. This can be useful at the beginning and end of your program.
Examples of monitoring techniques :
- Regular weight scale
- Measurement of body circumferences (waist, hips, arms)
- Body composition analysis (bioimpedance, DXA)
Note: the frequency of measurements must be reasonable to avoid obsessing over figures.
Adjust calorie intake according to results and sensations
Adjustment of daily calorie intake should be based on results obtained and personal sensations. If weight gain is unsatisfactory, or if you feel excessively tired, it may be time to review your calorie intake. It's a delicate balance between listening to your body and objectively analyzing your results.
Situation | Recommended fit |
Insufficient weight gain | Slightly increase calories |
Rapid weight gain | Reducing calories to avoid fat gain |
Fatigue or lack of energy | Reassess macronutrient distribution and intake frequencies |
Caution: all adjustments must be made gradually, without excess, and with caution.
Conclusion
To remember | In brief |
---|---|
🔍 MB Calculator | Black et al. formula for men and women |
🏃 Physical activity | Adding calories for sporting activity |
🧬 Factors | Age, gender, muscle mass, hormones, climate |
💪 Bodybuilding needs | Intensity, frequency and type of exercise determine additional needs |
🔄 Adjustments | Adjusting calories for weight gain or loss |
👤 Morphotype | Adaptation of needs according to ectomorph, mesomorph, endomorph |
🍽️ Food plan | Choice of macronutrients adapted to weight gain |
📊 Follow-up | Use of scales, circumference measurement, bioimpedance |
✏️ Caloric adjustment | Based on results and sensations |
🔄 Revaluation | Continuous adaptation required for nutritional and energy balance |
Successful mass gain relies on a thorough understanding of caloric requirements, integrating basal metabolism, training and individual variables such as age, gender and body composition.
Meticulous food planning and the right choice of nutrients are essential, as are regular monitoring of body mass and adjustment of daily calorie intake. Each step should be tailored to your personal goals, while listening to your body and reacting flexibly and thoughtfully to its needs.
Successful weight gain takes time (up to 5/6 months) and must remain a pleasure. It must not be seen as a constraint, and must be coupled with appropriate training and a varied, balanced diet adapted to weight gain.