Ideal Weight Calculator

There are several formulas used to calculate ideal body weight, each with its own approach and historical context. Understanding these differences can help you interpret your results more effectively.

The Hamwi Formula (1964)

Developed by Dr. G.J. Hamwi, this formula was originally intended for calculating dosages of medications. For men, it suggests 48 kg for the first 152 cm (5 feet) of height plus 2.7 kg for each additional cm. For women, it's 45.5 kg for the first 152 cm plus 2.2 kg for each additional cm.

The Devine Formula (1974)

Created by Dr. B.J. Devine for medication dosing, this formula is similar to Hamwi's but uses slightly different constants. For men: 50 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet.

The Robinson Formula (1983)

This formula was developed as a modification of the Devine formula. For men: 52 kg + 1.9 kg per inch over 5 feet. For women: 49 kg + 1.7 kg per inch over 5 feet.

The Miller Formula (1983)

The most recent modification, this formula suggests: For men: 56.2 kg + 1.41 kg per inch over 5 feet. For women: 53.1 kg + 1.36 kg per inch over 5 feet.

BMI Method

The Body Mass Index method uses a BMI of 22 (middle of the "normal" range) to calculate ideal weight. The formula is: weight = 22 × (height in meters)². This method is widely used but doesn't account for body composition.

While both BMI and ideal weight calculations aim to assess healthy weight ranges, they approach the problem differently and have distinct advantages and limitations.

Body Mass Index (BMI)

BMI is a simple calculation using only height and weight (weight in kg divided by height in meters squared). It categorizes individuals as underweight, normal weight, overweight, or obese based on fixed thresholds.

Advantages: Easy to calculate, widely used in population studies, good for assessing weight-related health risks at a population level.

Limitations: Doesn't distinguish between muscle and fat, doesn't account for body composition variations by age, sex, or ethnicity, less accurate for very tall or short individuals.

Ideal Weight Formulas

Ideal weight formulas typically consider height and gender, with some variations between formulas. They provide a single "ideal" weight rather than a range.

Advantages: More personalized than BMI (accounts for gender), often used in clinical settings for medication dosing, may be more intuitive for some individuals.

Limitations: Don't account for body composition, age, or muscle mass, different formulas can give significantly different results, may not be appropriate for all body types.

Which Should You Use?

Both metrics have value. BMI is excellent for population-level assessments and general health risk screening. Ideal weight formulas may be more useful in clinical settings or for individuals wanting a specific target weight.

For most people, considering both a healthy BMI range and ideal weight calculations can provide a more complete picture of their weight status.

While height and gender are the primary factors in ideal weight calculations, several other factors can influence what constitutes a healthy weight for an individual.

Body Composition

Muscle is denser than fat, so individuals with more muscle mass may weigh more than standard formulas suggest without being overweight. Athletes or very physically active people might fall into the "overweight" BMI category while being perfectly healthy.

Age

As people age, body composition changes - muscle mass tends to decrease while fat percentage increases. Some experts suggest slightly higher weight ranges may be appropriate for older adults, though this is debated.

Ethnicity

Different ethnic groups may have varying body compositions and fat distribution patterns. Some populations may have higher health risks at lower BMI levels, leading to calls for ethnicity-specific BMI thresholds.

Bone Structure

Individuals with larger bone structures may naturally weigh more. Frame size can be assessed by measuring wrist circumference relative to height.

Fat Distribution

Where fat is stored matters for health risks. Abdominal (visceral) fat is more strongly linked to health problems than subcutaneous fat. Waist circumference can be an important additional measurement.

Medical Conditions

Certain conditions may affect ideal weight recommendations. For example, individuals with obesity-related conditions like diabetes might benefit from being at the lower end of healthy weight ranges, while those with conditions causing muscle wasting might aim for the higher end.

Practical Considerations

Rather than focusing solely on a specific "ideal" weight, consider:

• How you feel at your current weight
• Your energy levels and physical capabilities
• Any weight-related health issues
• Your ability to maintain a stable, healthy weight long-term

Consulting with a healthcare provider can help determine the most appropriate weight range for your individual circumstances.