What is Ideal Weight?
Ideal body weight (IBW) is an estimate of the weight at which a person of a given height is considered to have the lowest health risks and optimal physical function. It is widely used in clinical settings for calculating medication doses, assessing nutritional needs, and setting weight management goals. Because body composition varies significantly between individuals, ideal weight is best understood as a healthy range rather than a single number.
Several formulas have been developed over the decades, each with slightly different results. The Devine formula (1974), originally used to calculate drug dosages, became the most widely used in medicine. The Robinson (1983), Miller (1983), and Hamwi (1964) formulas were developed independently and account for frame size differently. Our calculator shows all four so you can see the range and understand that "ideal weight" is not an exact science.
How to Use the Ideal Weight Calculator
- Enter your Height in feet and inches.
- Select your Gender — the formulas differ between men and women.
- Choose your Frame Size (small, medium, or large) — wrist circumference is a common proxy for frame size.
- Optionally enter your Current Weight to see how far you are from ideal.
- The table shows ideal weight from all four formulas, plus your healthy BMI weight range (18.5–24.9).
Why Use Our Ideal Weight Calculator?
- 4 Formulas at Once — Compare Devine, Robinson, Miller, and Hamwi side by side.
- BMI Range Included — See the healthy weight range for your height based on BMI 18.5–24.9.
- Frame Size Adjustment — Accounts for small, medium, and large body frames.
- Instant Live Results — No submit button needed; results appear as you type.
- Zero Data Collection — All computations happen locally in your browser.
Frequently Asked Questions
Ideal body weight is an estimate of the weight at which a person of a given height is expected to have the best health outcomes and lowest risk of weight-related disease. It is not a strict target — rather, it is a healthy range. Because muscle is denser than fat, athletes and muscular individuals may weigh more than the "ideal" weight while being perfectly healthy.
No single formula is universally most accurate, as "ideal" depends on the individual's muscle mass, bone density, and frame. The Devine formula is the most commonly used in clinical practice and is often the default in medical references. The Hamwi formula tends to give higher values for taller individuals. Using all four formulas and noting the range they agree on gives a better picture than relying on any single result.
Height is the primary input in most ideal weight formulas, but gender and frame size also play roles. Taller people generally have more bone and muscle mass supporting a higher ideal weight. Frame size (estimated from wrist circumference) accounts for the fact that two people of identical height can have significantly different bone structures, which influences healthy weight range.
BMI (Body Mass Index) is weight in kg divided by height in meters squared. A BMI of 18.5–24.9 is considered healthy for most adults. Our calculator converts this range to pounds for your specific height, giving you a healthy weight range. The ideal weight formulas (Devine, Robinson, etc.) typically produce values near the middle of the healthy BMI range, which is why they are closely related concepts.