Ideal Weight Calculator

How to Use

• Select your gender.
• Enter your height in feet and inches.
• Click "Calculate Ideal Weight" to see results from four formulas.
• The summary range shows the lowest to highest estimate across all formulas.

How It Works

This calculator uses four well-known formulas to estimate ideal body weight based on height. All formulas calculate a base weight for 5 feet of height and add an increment per inch above 5 feet. Devine (1974): Most widely used in medicine. Robinson (1983): A modification of Devine. Miller (1983): Tends to give slightly higher values. Hamwi (1964): One of the earliest formulas. Each formula produces a different estimate, so the range gives you a reasonable target.

What Is Ideal Body Weight?

Ideal body weight (IBW) is an estimated weight that is considered healthiest for a person based on their height and gender. Unlike a single magic number, ideal weight is better understood as a range, which is why this calculator shows results from four different formulas. Each formula was developed by a different researcher and gives a slightly different answer, reflecting the reality that there is no single "perfect" weight for any given height.

These formulas were originally developed for medical purposes, such as calculating drug dosages and setting ventilator parameters. Over time, they became popular tools for general health and fitness planning. It's important to remember that ideal weight formulas don't account for body composition, age, or ethnicity. A person with more muscle mass will naturally weigh more than these formulas suggest, and that's perfectly healthy. Think of the results as a reasonable starting point rather than a strict target, and always consult a healthcare provider for personalized guidance.

Frequently Asked Questions

Why do the four formulas give different results?

Each formula was developed using different study populations and methodologies. The Devine formula, for instance, was based on drug dosing research in the 1970s, while Robinson and Miller refined it with updated data. The variation between them reflects the inherent uncertainty in estimating an "ideal" weight from height alone.

Which formula should I trust the most?

The Devine formula is the most widely used in clinical settings, but no single formula is universally "best." Looking at the range across all four gives you a more realistic target zone. If you fall within or near that range and feel healthy and energetic, you're likely at a good weight for your body.

Why is there a minimum height of 5 feet?

All four formulas use 5 feet (60 inches) as a baseline and add weight for each additional inch. Below 60 inches, the math breaks down and produces unreliable or negative results. For individuals shorter than 5 feet, BMI or other tools are more appropriate for assessing healthy weight.

Does ideal weight change with age?

These formulas don't factor in age, but in reality your body composition shifts as you get older. Muscle mass tends to decrease and fat mass tends to increase with age. Many health professionals suggest it's acceptable to carry slightly more weight as you age, as long as you maintain muscle through regular exercise.

Should I use ideal weight or BMI?

Both tools serve slightly different purposes. Ideal weight gives you a concrete target number in pounds or kilograms, while BMI tells you whether your current weight is proportional to your height. Using both together gives you a well-rounded view of where you stand relative to general health guidelines.

Example Calculation

For a male standing 5'10" (70 inches, or 10 inches over 5 feet), here is what each formula produces: Devine: 50 + 2.3 × 10 = 73 kg (161 lbs). Robinson: 52 + 1.9 × 10 = 71 kg (156 lbs). Miller: 56.2 + 1.41 × 10 = 70.3 kg (155 lbs). Hamwi: 48 + 2.7 × 10 = 75 kg (165 lbs). This gives an ideal weight range of approximately 155 to 165 lbs. If this person weighs 170 lbs and exercises regularly, they are very close to the recommended range and likely in good health.

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