Ideal Weight Calculator

What Is Ideal Body Weight?

Ideal body weight (IBW) is a calculated reference based primarily on height and sex. Several formulas have been developed over the years, and they can produce different estimates for the same person.

Because there is no single universally correct ideal weight, this calculator shows several commonly referenced formulas rather than presenting one number as the definitive answer.

How Is Ideal Weight Calculated?

This calculator uses four classic ideal body weight formulas: Devine, Robinson, Miller, and Hamwi. Each formula uses a base weight at 5 feet and adds a fixed amount for each inch above 5 feet.

Devine Formula

For men:

IBW = 50 + 2.3 × (height in inches − 60)

For women:

IBW = 45.5 + 2.3 × (height in inches − 60)

Robinson Formula

For men:

IBW = 52 + 1.9 × (height in inches − 60)

For women:

IBW = 49 + 1.7 × (height in inches − 60)

Miller Formula

For men:

IBW = 56.2 + 1.41 × (height in inches − 60)

For women:

IBW = 53.1 + 1.36 × (height in inches − 60)

Hamwi Formula

For men:

IBW = 48 + 2.7 × (height in inches − 60)

For women:

IBW = 45.5 + 2.2 × (height in inches − 60)

Why Do the Formulas Give Different Results?

The formulas were developed at different times and use different assumptions. As a result, two formulas can produce noticeably different estimates for the same height.

Showing the four results together gives you a better understanding of the range instead of suggesting that one calculated number is universally correct.

Healthy Weight Range Based on BMI

This calculator also shows a separate BMI-based healthy weight range. For adults, a BMI between 18.5 and 24.9 is commonly used as a reference range.

The BMI-based range is calculated from height using:

Weight = BMI × height²

The lower end uses a BMI of 18.5, while the upper end uses a BMI of 24.9.

Ideal Weight Example

Consider a 30-year-old man who is 175 cm tall. Converting his height to inches gives approximately 68.9 inches, or about 8.9 inches above the 5-foot reference point.

The four formulas produce different estimates because each uses its own baseline and per-inch adjustment.

This illustrates why it is more useful to view ideal body weight as a reference range rather than as one exact target.

Is Ideal Weight the Same as Healthy Weight?

Not necessarily. Ideal body weight formulas are mathematical estimates based mainly on height and sex. They do not directly account for factors such as muscle mass, body composition, or individual differences.

A person's healthy weight can therefore differ from the result of an ideal-weight formula.

For another health measurement, you can use our BMI Calculator.

Frequently Asked Questions