A healthy weight is not a universal “ideal weight” set in stone. In practice, it is more of a range of healthy weights that are compatible with high energy levels, regular physical activity, a balanced diet, and a reasonable level of cardiometabolic risk.
This Protéalpes calculator takes a scientifically sound approach: it avoids relying on a "magic number" and offers a more useful interpretation of body weight by taking into account height, waist circumference, and the inherent limitations of traditional formulas.
Form Weight Calculator
[pa_tool slug="weight-and-body-shape-calculator"] [protealpes_cta id="whey-made-in-france"]Why it’s better to talk about “healthy weight” rather than “ideal weight”
Many online calculators promise to“calculate your ideal weight”using the Broca, Lorentz, or Creff formula.
These methods are of historical interest, but they remain theoretical benchmarks. They do not accurately describe body composition, do not distinguish between muscle mass and fat mass, and provide no information about the distribution of adipose tissue.
However, from a medical standpoint, this point is crucial: two people of the same weight and height can have very different metabolic profiles.
For this reason, this calculator does not aim to “determine the ideal weight” down to the nearest kilogram, but rather to estimate a more realistic range of healthy weights.12
The foundation of the tool: BMI is useful but incomplete
The first benchmark used isthe body mass index:
BMI = weight (kg) / height² (m²).
BMI has real value: it is simple, standardized, inexpensive, and useful as a screening tool at both the individual and public health levels. However, it does not directly measure body fat.
The CDC (Centers for Disease Control and Prevention) notes that it does not distinguish between fat, muscle, or bone, and that it should be interpreted in conjunction with other factors such as blood pressure, laboratory test results, lifestyle, and muscle mass.
In other words, a higher-than-normal BMI does not automatically mean excess body fat, especially in the case of a sports enthusiast or athlete; conversely, a “normal” BMI does not rule out excess abdominal fat.1
Furthermore, data on elite athletes also show that BMI in relation to performance varies significantly depending on the sport.
Waist circumference is just as important
To address this limitation, the tool includes, when possible, waist circumference and the waist-to-height ratio.
Today, this measure is increasingly used to better assess abdominal fat, which is more closely linked to the risk of type 2 diabetes, high blood pressure, and cardiovascular disease.
NICE also recommends using this ratio to classifycentral obesity: in practice, keeping the ratio below 0.5 is a good , simple rule of thumb to remember.
A study by Ashwell and Gibson also showed that this 0.5 threshold was better at identifying “early-stage risk” than the traditional matrix based solely on BMI and waist circumference. 2 3
What the result actually means
The tool’s result should therefore be interpreted as an ideal weight range, not as a directive to lose weight.
If your BMI is within a healthy range and your waist circumference remains moderate, you can be considered to be at a healthy weight.
If your BMI appears normal but your waist circumference is high, the interpretation should be more cautious. If you have a high amount of lean body mass or engage in regular physical activity, the interpretation should also be nuanced.
The NICE also notes that the waist-to-height ratio can be useful even in adults with high muscle mass, precisely because it provides a better indication of fat distribution than weight alone.12
An athlete's ideal weight also depends on their sport
For an athlete, it is important to distinguish between a healthy weight and a weight that promotes peak performance.
Data from elite athletes show that there is no single optimal weight or BMI that applies to all sports.
The body types of top athletes vary greatly depending on the demands of their sport. International marathon runners, for example, tend to have relatively low weights and BMIs, while elite sprinters, basketball players, and rowers have significantly higher body weights. In professional cycling as well, climbers are generally lighter than sprinters.
Above all, this comparison highlights one thing: a lower BMI does not necessarily mean better performance.
Weight can be an advantage or a disadvantage depending on what the athlete needs to do: move their body for several hours, generate high absolute power, jump, accelerate, or withstand contact.
Even within the same sport, the “ideal weight” can vary
In fact, discipline alone is not always enough. The role the athlete plays also affects the physical demands.
In running, the body types seen at the highest levels differ significantly between the marathon and the 100-meter dash. In the Tour de France, mountain specialists are generally lighter than sprinters. In soccer, goalkeepers are generally larger than midfielders; in basketball, centers are naturally taller and heavier than guards.
This explains why striving to achieve a single "ideal" BMI for athletes would make little sense. The weight that supports peak performance depends on the sport, the position, and the athlete’s individual qualities.
Body composition matters more than weight alone
Finally, two athletes of the same weight may perform very differently depending on the ratio of muscle mass to body fat.
Studies conducted on various professional athletes show that greater lean body mass may be associated with better power performance, particularly in jumping and certain explosive movements. Conversely, higher body fat can be a hindrance when one must frequently shift one’s own body weight.
These correlations do not mean that an athlete would automatically improve their performance by gaining or losing weight. Rather, they show why body composition, the power-to-weight ratio, and the demands of the sport provide more insight than the number displayed on the scale.
The calculator presented here should therefore be viewed as a general guide to health and body composition. For an athlete seeking to optimize performance, determining an ideal weight also requires monitoring performance, recovery, body composition, and weight trends over time.
A healthy weight also depends on lifestyle
Form weight isn't just a matter of a formula. It also depends on:
- energy expenditure,
- sleep,
- the level ofphysical activity,
- in the food industry,
- of age,
- sex,
- lifestyle habits.
The WHO guidelines state that adults should aim for at least 150 to 300 minutes of moderate-intensity physical activity per week, or 75 to 150 minutes of vigorous-intensity activity, along with muscle-strengthening activities at least two days a week.
This isn't just a minor detail: trying to "reach your target weight" without preserving muscle mass or establishing a sustainable routine often leads to short-lived results. 4
A tool is not a diagnosis
Finally, it’s important to remember that a body mass index calculator is meant to be a guide, not a medical opinion.
It is useful for adults who want to maintain their weight, understand their current situation, or track their progress. It is less useful for teenagers, during pregnancy, in cases of illness, or for certain highly atypical cases.
And if the goal is weight loss, the right benchmark isn’t necessarily reaching a “theoretical ideal weight,” but rather achieving realistic and sustainable progress: the NHLBI notes that losing 5 to 10% of one’s body weight can already significantly improve health and quality of life.
To put it simply, the right question isn’t just “How much should I weigh?”, but rather: Within what weight range can I stay healthy, function well, recover, and—if I play a sport—best demonstrate the skills required for my sport? 5
Scientific references and sources
2 Management of overweight and obesity by National Institute for Health and Care Excellence (NICE)
3 Waist-to-height ratio as an indicator of ‘early health risk’: simpler and more predictive than using a ‘matrix’ based on BMI and waist circumference by Margaret Ashwell et al.
4 WHO guidelines on physical activity and sedentary behavior by World Health Organization (WHO)
5 Overweight and Obesity – Treatment by National Heart, Lung, and Blood Institute (NHLBI)
