# Ideal Weight Calculated By Several Methods

The ideal weight for a given height, and by age is determined according to several formulas that we will review. However keep in mind that this ideal is still an approximation, since some factors such as density of body muscles are not taken into account and will weigh your opinion.

## Body mass index, BMI

It depends on the height and weight and determines the excess fat, based on the extra weight compared to the standard.
The invention is attributed to L. A. J. Quételet in 18 th century and serves to insurance companies to evaluate the cardiovascular risk. The WTO also uses this index as a risk factor associated with the obesity because there is a relationship between BMI and mortality.

The formula is:

`IMC = weight / ( height  x height )`

The size is expressed as a meter with decimals. Example for a weight of 70 kg and a height of a meter and sixty :

`70 / ( 1,60 x 1,60 )`

It is estimated that the weight is acceptable when the BMI calculated is between 18 and 25 and that the risk of death increases when we are closer or beyound to those values. We must take into account all cases, such as sports with a more important muscle mass, etc...

### Interpretation of BMI

 IMC Interpretation < 15 Malnutrition 15 - 18,5 Thinness 18,5 - 25 Normal 25 - 30 Overweight 30 - 35 Fatness 35 - 40 Obesity > 40 Extreme obesity

## The Monnerot-Dumaine's formula

This formula provides an ideal weight and overweight according to height and circumference of the wrist (CW).

`Ideal weight = (height  - 100 + (4 * CW ) ) / 2`

## The Broca's formula

In this very schematic case, it is only the height that is taken into account in determining ideal weight or obesity.
The formula is simple:

`Ideal weight = height - 100`

## The Creff's formula

This is an improvement from the previous formula, age and height are taken into account in determining ideal weight or obesity. The Broca's formula is even more improved with an indice of slimness:

Slimness:
Gracile: indice 0.9
Normal: indice 1
Stocky: indice 1.1

The Broca formula is so modified:

`Ideal weight = (height - 100 + (age / 10)) x 0.9 x indice`

## The Lorentz's formula

More simplistic it evaluate the ideal weight only by the height and the sex male/female. It also wants to improve Broca's formula.

`Ideal weight male = (height - 100 - ((height - 150) / 4)`
`Ideal weight female = (height - 100 -  ((height - 150) / 2)`

## Ideal weight calculation

All parameters outlined above are taken into account, which allows comparison of formulas.