Ideal Weight Calculator
How the Ideal Weight Calculator Works
Ideal body weight (IBW) is an estimate of a healthy weight for a given height and sex, originally developed to help with medication dosing and clinical assessment. This calculator applies several classic formulas at once and shows the resulting range, so you get a rounded picture rather than a single arbitrary number. It uses only your height and sex, which makes it quick but also means it cannot capture your individual build.
The Formulas
The tool draws on well-known equations. The Devine formula uses 50 kg + 2.3 kg × (inches over 5 ft) for men and 45.5 kg + 2.3 kg × (inches over 5 ft) for women. Robinson, Miller, and Hamwi formulas follow the same structure with different base weights and per-inch increments. Because they diverge slightly, presenting them together gives a realistic target band instead of false precision.
Interpreting Your Result
Read the output as a range, and expect a healthy weight for you to fall somewhere inside or near it. The formulas assume an average frame and do not account for muscle, so athletes and people with larger builds will often exceed their calculated IBW while remaining healthy. Conversely, sitting within the range does not by itself confirm good health if body composition or fitness is poor.
When to Use It
Ideal weight estimates are helpful as one reference point when setting a body-weight goal, and they complement BMI, waist measurements, and body fat readings for a fuller view. They are not a diagnosis or a mandate. These results are general estimates for informational purposes only; consult a healthcare professional or registered dietitian for a personalized assessment before pursuing significant weight change.
Frequently Asked Questions
How is ideal body weight calculated?
The calculator uses established formulas such as Devine, Robinson, Miller, and Hamwi that estimate weight from height and sex. The Devine formula, for example, is 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch over 5 feet for women.
Why do the formulas give different numbers?
Each formula was derived from a different population and era, so they weight height slightly differently. Rather than trusting one, it is useful to see the range they produce. The truth for any individual usually lies somewhere within that spread, not at a single exact figure.
Is ideal weight the same as a healthy weight?
Not exactly. These formulas ignore body composition, frame size, and muscle mass, so a fit, muscular person may sit above their 'ideal' weight yet be perfectly healthy. Ideal weight is best viewed as a reference range, not a strict target.
Does frame size matter?
Yes. People with larger bone structures naturally carry more weight at the same height. Some clinicians adjust ideal weight by roughly 10% up or down for large or small frames, which is one reason a range is more meaningful than a single number.
How should I use my ideal weight result?
Use it as a rough orientation alongside BMI, waist circumference, and body fat percentage. If your weight is far outside the estimated range, treat that as a prompt to discuss your health with a professional rather than as a diagnosis.