Ideal Weight Calculator

Ideal Weight Calculator

Ideal Weight Calculator

Ideal Weight Calculator Explained

The Ideal Weight Calculator is a useful tool to estimate a healthy range of body weights based on various formulas widely known. It considers an individual’s height, gender, and sometimes age to give weight suggestions. The formulas were initially intended for use in medicine, especially to determine appropriate drug dosages. Currently, they also find applications in the fields of sports and health screening.

What Is Ideal Body Weight (IBW)?

At some time or another, almost everyone has asked themselves: “What do I weigh?” The concept of an “ideal” weight is familiar, yet it tends to be based less on true health science and more on media and societal expectations. In the real world, IBW is not determined by an individual’s appearance but by useful measures created for clinical and drug use.

At first, IBW was used by physicians to determine the amount of medication a patient should be given. Eventually, it became a reference value in health science and sports science as well.

It is also essential to keep in mind that ideal weight doesn’t necessarily mean perfect health. These calculations don’t take into account variables such as muscle mass or body composition. Therefore, healthy people with a high muscle mass can be heavier than their “ideal” and yet absolutely healthy.

How Much Should You Weigh?

There is no single right answer. A healthy weight depends on a variety of factors, including:

  • Age
  • Sex
  • Height
  • Body Frame Size
  • Muscle-to-fat ratio
  • Lifestyle and overall health

Although IBW calculations provide helpful guidelines, your eating and exercise habits are much more important than meeting a particular number on the scale.

Factors That Affect Ideal Weight

1. Age
After puberty, height usually settles at 14–17 years of age. However, with increasing age, lean muscle mass reduces, and body fat can rise even without significant weight changes. Up to age 70, men and women lose an average of 1.5 to 2 inches in height. This natural change results in IBW varying minimally by age, though.
2. Gender
Men and women have inherently varying body composition. On average:
  • Men have more muscle mass and heavier bones.
  • Women have more body fat and weigh less on average at the same height.
So, two individuals of the same height but opposite sexes might have a different ideal weight.
3. Height
Height is a basic determinant of IBW. Tall people generally possess more bone mass, more muscle, and thus greater body weight. A woman and a man of the same height will also vary in ideal weight because of body structure.
4. Body Frame Size
Body frame size is your bone structure and is usually calculated by measuring wrist circumference against height. Here’s how it breaks down: For Women:
Height Small Frame Medium Frame Large Frame
Under 5’2″ Wrist < 5.5″ Wrist 5.5″–5.75″ Wrist > 5.75″
5’2″–5’5″ Wrist < 6″ Wrist 6″–6.25″ Wrist > 6.25″
Over 5’5″ Wrist < 6.25″ Wrist 6.25″–6.5″ Wrist > 6.5″
For Men:
Height Small frame Medium frame Large frame
Over 5’5″ Wrist 5.5″–6.5″ Wrist 6.5″–7.5″ Wrist > 7.5″
Those with a larger frame will naturally weigh more, even at the same height.

Popular Ideal Weight Formulas

These equations all operate on the same principle of beginning at a base weight at 5 feet and increasing by a fixed amount for each inch over 5 feet. All having been constructed with differing objectives, they follow the same formula.
Formula  Men Women Comments
Hamwi (1964) 48 kg + 2.7 kg/inch over 5 ft 45.5 kg + 2.2 kg/inch over 5 ft Originally for drug dosing
Devine (1974) 50 kg + 2.3 kg/inch over 5 ft 45.5 kg + 2.3 kg/inch over 5 ft Most widely used IBW formula
Robinson (1983) 52 kg + 1.9 kg/inch over 5 ft 49 kg + 1.7 kg/inch over 5 ft Modified version of Devine formula
Miller (1983) 56.2 kg + 1.41 kg/inch over 5 ft 53.1 kg + 1.36 kg/inch over 5 ft Another adjustment to Devine

Another modification of Devine

Example (Using Devine Formula):
If you are a 5’10” male:
Height above 5 feet = 10 inches
Add: 2.3 × 10 = 23 kg
Base: 50 kg
Ideal Weight = 73 kg (~161 lbs)

Healthy Weight Using BMI

Body Mass Index (BMI) is another measure that can be used to evaluate healthy weight. The World Health Organization (WHO) considers the following healthy BMI range:
18.5 – 24.9
To determine a healthy weight for your height based on BMI:

Calculate your BMI = Weight (kg) ÷ Height² (m²)
Reverse the equation to calculate an appropriate healthy weight range for your height.

Important Note: BMI is commonly used in medical evaluation but doesn’t take into account muscle mass, bone density, or fat distribution. That’s why athletes or bodybuilders can have “high” BMIs even if they are healthy.

Healthy BMI for Children and Teens

The formulas above are for adults (18+ years old). IBW is measured differently for children and teens. The CDC (Centers for Disease Control and Prevention) employs BMI percentiles on the basis of gender and age:

Healthy Range: Between 5th to 85th percentile
These percentiles are followed through growth charts broken down by the specific gender of boys and girls from 2 to 20 years old.

Drawbacks of Ideal Weight Formulas

IBW formulas are good but are only rough estimates. They do not take into account:
  • Body composition (fat vs. muscle)
  • Activity level
  • Medical conditions
  • Disability or chronic disease
Because these equations try to fit most people, they might not be perfect for everybody particularly those who are extremely muscular, extremely short or tall, or have special health requirements.