Expenditure and Energy Requirement Calculator


Formula to use:

Energy expenditure: kCal

Sedentary person: kCal

Active person: kCal

Serum Albumin Level Adjusted With C-Reactive Protein

The energy expenditure given is basic, at rest and on an empty stomach over 24 hours. Energy requirements are also given for 24 hours.

      Currently, the Black & al formula is the reference. It is selected by default.

What is Basal Metabolism?

Basal Metabolism is the body's incompressible need to survive, it is equivalent to ~40kcal/m2/h (approx. 1300-1600kcal in adults): ~60% of the Daily Energy Expenditure, 45% in the subject very active 70% in sedentary subjects. It is positively correlated with lean mass (biologically active mass), it is the cornerstone of human health.

We note the importance of physical activity on the phenomena of tissue construction (bone, muscle, etc.) which will initially stabilize the active tissues and then, depending on the intensity and volume of the effort, increase these same tissues (particularly muscular but not only…). Lean mass decreases in cases of physical inactivity, and malnutrition (hence the importance of protein-carbohydrate-lipid-energy renutrition), with age, and therefore the Basal Metabolism is lower, decreasing naturally with age. time if no effort is provided upstream!

The Basal Metabolism increases during an increase in body temperature or hyperthermia, during an attack, physical activity, tobacco, pregnancy, hyperthyroidism, and stress… during any physical, physiological, and/or psychological attack. We understand better to infer it sometimes from the early weight loss during the beginning of draconian, wacky diets, not adapted at all levels for the human being who receives this more like an attack, requiring a little more energy to s adapt, but with what results in the end! Weight gain generally!

What influences basal metabolism?

Postprandial thermogenesis

Also called specific dynamic action, it is food-induced. We expend energy by eating, digesting, and assimilating!


This is the cost of maintaining homeothermy (~37°C), of our core temperature in a nutshell. Neutrality in the air is 20-22°C and 32-33°C in water. The closer we are to thermal neutrality, the less we spend, and the more the needs are reduced. Hence, sometimes, the interest in not overheating our habitat or swimming in slightly cooler water stimulates the metabolism. To return to the bodyweight dear to our Western societies, this parameter is key in terms of increasing the imbalance of the energy balance by reducing the energy expenditure linked to the minimization of the expenditure of thermoregulation. The sedentary lifestyle with the evolution of society comes in synergy to accelerate this imbalance.

Muscular exercise

It is related to physical activity. Expenditure (concept of energy cost) varies according to a large number of parameters: aerobic activity, anaerobic activity, body weight, repetition, duration of exercise, ergonomics of effort, etc. Promoting basic life activities human: walking, running, cycling, swimming.