Ideal Weight Calculator

Ideal body weight (IBW) is calculated using formulas based on height and gender. The most widely used is the Devine formula (1974): For men, IBW = 50kg + 2.3kg per inch over 5 feet. For women, IBW = 45.5kg + 2.3kg per inch over 5 feet. Our calculator uses multiple formulas to give you a reliable range.

Men and women have different ideal weights at the same height due to differences in muscle mass and body composition. A 5'10" man has an ideal weight around 73kg, while a 5'10" woman has an ideal weight around 66kg. Our calculator automatically adjusts based on your gender.

Ideal weight formulas give you a specific target, while BMI gives you a healthy range (18.5-24.9). Both are useful: ideal weight is your target, BMI range shows the bounds of healthy weight. Our calculator shows both so you can see how they compare.

We use four ideal weight formulas: Devine (1974) — most widely used, Robinson (1983) — modified Devine, Miller (1983) — tends higher, and Hamwi (1964) — original formula. Different formulas suit different body types, which is why we show a range rather than a single number.

Ideal body weight (IBW) is a height-based estimate of the weight statistically associated with the lowest health risk for an adult of your height and sex. It was originally developed not for aesthetics but for clinical dosing, and it remains a quick reference point for a healthy target.

It matters because carrying weight far above or below this reference is linked to health outcomes. The CDC notes that excess body weight raises the risk of type 2 diabetes, high blood pressure, and heart disease, while the World Health Organization (WHO) uses similar height-weight standards to track population health.

Keep two things in mind:

• IBW is a reference range, not a strict rule for every individual.
• It works best alongside other measures such as body mass index (BMI), waist circumference, and body composition.

To use this calculator, enter your gender and height, then read your ideal weight range — the tool applies the Devine, Robinson, Miller, and Hamwi formulas at once and averages them.

Here is a worked example for a woman who is 5'6" (168 cm):

• Convert height: 66 inches is 6 inches over 5 feet.
• Devine (women): 45.5 kg + (2.3 kg x 6) = 59.3 kg.
• Robinson (women): 49 kg + (1.7 kg x 6) = 59.2 kg.
• The calculator blends all four formulas into a range of roughly 56 to 62 kg.

Measure your height without shoes for accuracy. The National Institutes of Health (NIH) recommends comparing your result to a healthy BMI range rather than treating any single figure as absolute.

The most common mistake is treating ideal body weight as one exact number you must hit, when it is really a range that spans several kilograms across formulas and frame sizes.

Watch for these frequent errors:

• Ignoring muscle mass — the American College of Sports Medicine (ACSM) notes that muscular athletes can be healthy above their calculated IBW.
• Using the wrong height — measuring in shoes or slouching skews every formula.
• Applying adult formulas to teens — the CDC uses age-and-sex growth charts for anyone under 20, not IBW formulas.
• Confusing IBW with a weight-loss goal without checking body composition.

Avoid these by treating IBW as a guide and confirming any weight goal with a healthcare professional, as the NIH advises.

Age has only a minor effect on ideal body weight because the standard formulas depend on height and sex, not age. Your IBW figure stays essentially the same from your twenties onward, provided your height has not changed.

What does shift with age is body composition. The National Institutes of Health (NIH) reports that adults tend to lose muscle mass and gain fat with age, a process called sarcopenia, so two people at the same weight can have very different health profiles.

Practical takeaways:

• Your target weight range stays stable, but maintaining muscle through resistance training matters more over time.
• Height can decrease slightly after 50, so remeasure periodically.
• The CDC suggests monitoring waist size alongside weight as you age.

Body frame size can shift your ideal weight by roughly 10 percent in either direction because larger skeletal frames carry more bone and structural mass. Someone with a large frame may sit healthily near the top of the range, while a small-framed person fits the lower end.

A simple way to estimate frame size is wrist circumference relative to height, a method referenced in clinical height-weight tables.

General guidance:

• Small frame — aim toward the lower part of your calculated range.
• Medium frame — the mid-range figure usually fits.
• Large frame — the upper part of the range is appropriate.

Because frame size is an estimate, the NIH recommends using it to interpret a range rather than to pin down a single exact target weight.

Athletes and highly muscular people are often healthy at a weight well above their calculated ideal body weight, because these formulas cannot distinguish muscle from fat. Muscle is denser than fat, so a fit, lean body can weigh more than the IBW figure suggests.

The American College of Sports Medicine (ACSM) emphasizes body composition — the ratio of lean mass to fat mass — over scale weight alone for active individuals.

If you train seriously, consider these points:

• Learn how to measure body fat percentage or use a body composition scan rather than IBW as your primary metric.
• The CDC and American Heart Association still recommend watching waist circumference as a marker of visceral fat.
• Treat IBW as a rough floor, not a ceiling, when you carry substantial muscle.

Reaching an exact ideal weight is not always the healthiest goal — staying within a healthy range while improving overall health markers usually matters more. The number on the scale is one signal among many.

The Consumer-focused guidance from the CDC and NIH points to several indicators that together describe health better than weight alone:

• Waist circumference as a measure of abdominal fat.
• Blood pressure, blood sugar, and cholesterol levels.
• Physical activity — the CDC recommends about 150 minutes of moderate activity weekly for adults.
• Diet quality, following USDA dietary guidance.

Use your ideal weight as a directional target, not a verdict. If you are far outside your healthy range, the American Heart Association advises setting gradual, sustainable goals with a healthcare provider.