Ideal Weight Calculator

There is no single "most accurate" formula, as all classic equations (Devine, Robinson, Miller, Hamwi) are mathematical models based on historical population averages. The Devine formula is the most widely used in clinical pharmacology to calculate dosage. The Robinson and Miller formulas tend to yield slightly higher estimates for women and lower estimates for men, making them popular in general fitness contexts. Our calculator shows the range across all five methods.

Classic formulas use a baseline height of 5 feet (60 inches or 152.4 cm) as their mathematical anchor point. For every inch above 5 feet, a set multiplier of weight is added. Because these equations assume a linear growth rate, applying them to heights below 5 feet can produce unrealistically low or even negative numbers. For shorter individuals, standard BMI ranges are a far more reliable health guide.

The Hamwi formula was developed in 1964 by Dr. J.R. Hamwi. For men, the formula is: 48.0 kg + 2.7 kg per inch over 5 feet. For women, it is: 45.4 kg + 2.2 kg per inch over 5 feet. It is one of the oldest and simplest methods, often yielding slightly higher weight targets for tall individuals.

Classic ideal weight formulas do not account for skeletal frame size, which can vary weight by ±10%. To estimate your frame size, wrap your thumb and index finger around your opposite wrist. If they overlap, you have a small frame; if they touch, a medium frame; if they do not meet, a large frame. A person with a large frame should target the upper end of the ideal weight range.

Not necessarily. Your "healthiest weight" is determined by factors like body fat percentage, metabolic health markers (blood pressure, blood sugar, cholesterol), muscle mass, and fat distribution. A person can weigh more than their "ideal weight" due to high muscle mass and still be in peak health. Use these formulas as a reference range rather than an absolute target.

No, these standard clinical formulas do not factor in age. However, research indicates that older adults (65 years and older) are generally healthier and have lower mortality rates if they carry a slightly higher weight (BMI 25–27) than younger adults, to help protect against bone fractures and sarcopenia.

The Devine formula was created in 1974 by Dr. Ben Devine. For men, it is: 50.0 kg + 2.3 kg per inch over 5 feet. For women, it is: 45.5 kg + 2.3 kg per inch over 5 feet. It was originally designed to calculate clear drug dosages (like theophylline) but became the medical standard for ideal body weight.

If your current weight is above your ideal range and you have a high body fat percentage, target a moderate calorie deficit to lose fat safely. If you are below the range, aim for a caloric surplus combined with strength training to gain healthy weight (lean muscle). If you are within the range, focus on recomposition (strength training to build muscle while losing fat).