Caloric and macronutrient requirements calculator
Recommended macronutrient breakdown (approx.)
Macronutrients are the three categories of nutrients that provide the energy needed for the body to function and adapt to physical activity: proteins, carbohydrates, and fats.
Calculating your macronutrients helps you determine the exact amounts of each that your body needs every day, based on your weight, level of physical activity, and goal: maintaining your current weight, building muscle, or reducing body fat.
This calorie and macronutrient calculator serves as a starting point. The results it provides are estimates based on standard formulas; they should be adjusted based on individual response over several weeks.
In a nutshell
- Macronutrients are proteins (4 kcal/g), carbohydrates (4 kcal/g), and fats (9 kcal/g).
- Calculating macros involves two steps: estimating total energy expenditure (TEE), then allocating calories among the three macronutrients based on your goal.
- Standard formulas (Mifflin-St Jeor, revised Harris-Benedict) provide a reliable estimate of basal metabolic rate, but they are still only approximations.
- There is no one-size-fits-all guideline: recommended ranges vary depending on the sport, age, and body composition.
- Monitoring over 2 to 4 weeks and making gradual adjustments are more effective than trying to find the perfect ratio right from the start.
What are macronutrients?
The three macronutrients differ in their roles and energy density.
Proteins (4 kcal/g) are the building blocks of muscle tissue, enzymes, and hormones. They play a key role in post-workout recovery and in maintaining lean body mass during calorie restriction.
Carbohydrates (4 kcal/g) are the primary source of energy for muscle and brain activity. Stored as glycogen in the liver and muscles, they serve as the primary fuel source during moderate- to high-intensity exercise.
Fats (9 kcal/g) are essential for the synthesis of steroid hormones, the transport of fat-soluble vitamins (A, D, E, K), and the protection of organs. Their high caloric density means they are often consumed in the wrong amounts—either too much or too little—when the goal is to change body composition.
Step 1: Calculate basal metabolic rate and total energy expenditure
Basal metabolic rate (BMR) refers to the body’s energy expenditure at rest—that is, the minimum amount of energy required to maintain vital functions. The Mifflin-St Jeor formula is now considered one of the most accurate for the general population:¹
- Men: MB (kcal/day) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
- Women: MB (kcal/day) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
Total energy expenditure (TEE) is calculated by multiplying MB by a physical activity coefficient:
| Activity level | Coefficient |
|---|---|
| Sedentary (little or no exercise) | x 1,2 |
| Moderately active (1 to 3 sessions per week) | x 1,375 |
| Moderately active (3 to 5 sessions per week) | x 1,55 |
| Very active (6 to 7 sessions per week) | x 1,725 |
| Extremely active (physical work + intense training) | x 1,9 |
These coefficients are averages derived from the nutritional literature. They do not take into account individual variations in metabolism.
Comparison of the main formulas
| Formula | Year | Study population | Age limits | Weight limits | Precision | Recommended use |
|---|---|---|---|---|---|---|
| Harris-Benedict | 1919 | 136 men, 103 women, 94 children | 21-70 years | 25-125 kg | ±14% (general population) | Population corresponding to original criteria |
| Roza-Shizgal | 1984 | Larger samples than H&B | Adults | Normal weight | ±14% (improved) | Healthy general population |
| Black et al. | 1996 | Large, diversified samples | >60 years (optimal) | Overweight accepted | High for specific populations | Elderly and overweight people |
| Mifflin-St Jeor | 1990 | Diverse modern population | Adults | Broad spectrum | Considered the most accurate | Modern general population |
Step 2: Adjust the macronutrient breakdown based on your goal
Once the TED has been calculated, the target calorie intake and macronutrient distribution are adjusted to align with the goal.
Weight maintenance: Calorie intake equals the Daily Energy Requirement (DER). The standard macronutrient breakdown for an athlete is 25–35% protein, 40–50% carbohydrates, and 20–30% fat. These ranges are intentionally broad: they must be adjusted to fit each individual’s profile.
Muscle gain: During a bulking phase, a moderate calorie surplus of 200 to 400 kcal above the daily energy requirement (DER) is generally sufficient to stimulate muscle growth while limiting fat gain. The recommended protein intake cited in the literature ranges from 1.6 to 2.2 g per kilogram of body weight per day for strength athletes.²
Reducing body fat: During a muscle-building phase, a controlled calorie deficit of 300 to 500 kcal below daily energy expenditure (DEE) helps reduce body fat while preserving muscle mass, provided that protein intake remains sufficient. Larger deficits increase the risk of muscle catabolism and chronic fatigue.
This principle is based on the energy balance: when calorie intake exceeds energy expenditure, weight tends to increase; conversely, when intake is lower than total energy expenditure (TEE), the body draws on its reserves. The quality of macronutrient distribution then influences body composition, recovery, and performance.
How can you hit your macros every day?
Calculating your macros is one thing; hitting your goals consistently is another.
Food tracking apps allow you to track your intake over several days and identify recurring imbalances: too much or too little protein, an excessive concentration of carbohydrates in certain meals, or underestimated fat intake.
The distribution of protein intake throughout the day is more important than the exact amount consumed at each meal. Consuming protein in 3 to 5 meals of 20 to 40 grams each appears to be more effective for muscle protein synthesis than consuming the same amount in just one or two meals, according to available data.³
Nutritional needs change depending on body weight, fitness level, and goals. Recalculating every 6 to 8 weeks—or whenever there is a significant change in weight—helps ensure that the nutrition plan remains effective.
When it comes to supplementation, whey protein is a convenient way to meet recommended daily protein intake, particularly during the post-workout window when food options may be limited. Protéalpes formulas are made with high-quality whey isolate and contain no additives or sweeteners.
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Scientific references and sources
2 A systematic review, meta-analysis, and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults by Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Phillips SM et al.
3 The timing and distribution of protein intake during prolonged recovery from resistance exercise alter myofibrillar protein synthesis by Areta JL, Burke LM, Ross ML, Camera DM, West DWD, Phillips SM, et al.
