Ideal Weight Calculator

How Much Should I Weigh?

Almost everyone has at one point attempted to lose weight or have at least known somebody who has attempted to do this. This may largely be due to what we see as “ideal” body weight, which is primarily shaped by what is shown and told in the media, including social media, TV, movies, magazines, etc. Although ideal body weight (IBW) can be defined today as what looks good (and the imagery of IBW is undeniably visually appealing) IBW was created to estimate dosages for medical purposes, and these equations that create the ideal body weight are in no way connected to what a person’s body should look like at that weight. Subsequently it has been understood that the metabolism of certain drugs is based more on IBW than on total body weight. More recently IBW has become more standard for use across sports, as many sports classify based on body weight.

It is important to understand that the IBW does not provide a perfect measurement of a person’s ideal body weight. One of the main limitations of IBW is that the formula is not designed to take the proportion of body fat or muscle into consideration when determining a person’s weight. As a result, it is possible that highly fit, healthy athletes, can be considered overweight based on their IBW. This is why it is essential to view IBW from the vantage point of an imperfect measurement of weight and not one that necessarily indicates health or even weights that a person should strive for; it is possible for someone to be over their “IBW,” as well as under their “IBW” and be perfectly healthy too.

Determining a person’s weight is not a perfect science, since it is highly individual. Nonetheless, to this point, there is not a definitive measurement—whether IBW, body mass index (BMI), or any other formula—that can conclusively indicate a person’s healthy weight. They are simply references and it is more important to focus on healthy lifestyle choices (regular exercise, eating a variety of unprocessed foods, getting sufficient sleep, etc.) rather than succumbing to the pressures of what one should weigh based on an unqualified formula.

Age

Theoretically, age should not play a significant role in determining your IBW after girls are typically done growing at 14-15 and boys are typically done growing at 16-17. In fact, it is expected that human males will lose 1.5 inches in height and human females will lose 2 inches in height by the age of 70. It should be noted that as a person ages, they lose lean muscle mass and it is easier to gain excess body fat. This is a natural process, but you can work to counteract the natural aging process by being responsible with your dietary intake, exercise, stress management, and sleep.

Gender

In general, women have less weight compared to men, though biologically women hold more body fat naturally. The basis for this is that a male body tends to have more muscle mass, and muscle weighs more than fat. In addition, women also tend to have lower bone density than men. And last, but certainly not least, men are generally taller than women.

Height

The taller you are, the more muscle mass and body fat you have, which would obviously result in weight. A male should be about 10-20% heavier than a similarly sized female.

Body Frame Size

Body frame size is another important variable that can influence the measurement of desirable weight. Body frame size is usually classified as small, medium or large-skeleton. Body frame size is measured from the wrist circumference with respect to a person’s height, as demonstrated below.

For Women:

• Height less than 5’2″

o Small skeleton = wrist circumference less than 5.5″

o Medium skeleton = wrist circumference between 5.5″ and 5.75″

o Large skeleton = wrist circumference greater than 5.75″

• Height between 5’2″ and 5′ 5“

o Small skeleton = wrist circumference less than 6″

o Medium skeleton = wrist circumference between 6″ and 6.25″

o Large skeleton = wrist circumference greater than 6.25″

• Height greater than 5′ 5″

o Small skeleton = wrist circumference less than 6.25″

o Medium skeleton = wrist circumference between 6.25″ and 6.5″

o Large skeleton = wrist circumference greater than 6.5″.”

For Men:

• Height greater than 5′ 5″

o Small boned = Wrist size must be between 5.5″ and less than 6.5″

o Medium boned = Wrist size must be between 6.5″ and less than 7.5″

o Large boned = Wrist size greater than equal to 7.5″

Simply put, a large-boned person will weigh more than a small-boned person at the same height. Thus a person’s frame size can potentially factor into measurements like IBW or BMI.

Formulas for Finding the Ideal Weight

The IBW formulas were primarily created to assist in determining drug dosages. All of the formulas utilize the same structure of a base weight at 5 feet of height and an established weight increase for each inch above 5 feet of height. For example, if I am a male who is 5’10” and I am estimating my ideal body weight with the Devine formula, I will add (2.3 × 10) kg to 50 kg, resulting in 73 kg (~161 lbs).

The formulas differ in the values used based on the research conducted by the scientists who created them and their findings. The Devine formula is the most widely used formula for the assessment of IBW.

1. J. Hamwi Formula (1964)

Invented for medicinal dosage purposes.

1. J. Devine Formula (1974)

Similar to the Hamwi Formula, it was originally intended as a basis for medicinal dosages based on weight and height. Over time, the formula became a universal determinant of IBW.

1. D. Robinson Formula (1983)

Modification of the Devine Formula.

1. R. Miller Formula (1983)

Modification of the Devine Formula.

Healthy BMI Range

The World Health Organization (WHO) proposes a healthy BMI range of 18.5 – 25 for males and females. In knowing the BMI range, one can find a healthy IBW for any height.

BMI is a commonly used measure to determine IBW. It is frequently used in medicine as a quick reference to indicate continued health problems. In general, the higher the BMI the more likely a person is going to have health complications such as obesity, diabetes, heart disease, etc. To some degree, it is an informal indicator that doctors use to inform their patients of possible health problems, especially when the BMI is up progressively, and it is the current official way to track obesity levels for individuals.

Limitations of our IBW calculator

All formulas and methods have their limitations. Because they are intended to be as applicable to as wide a range of people as possible, they cannot be very precise for any given individual. The formulas take into consideration only height and gender, but not physical disabilities, extreme individuals, activity level, or composition, which is muscle mass to fat mass, ratio. Our Ideal Weight Calculator was intended to be guidance only based on some of the more popular formulas. Meaning that the results do not render an “ideal weight” that each individual must achieve.