Ideal Weight Calculator
Find your healthy weight range by height and gender using four medical formulas.
Our free ideal weight calculator helps you find a healthy weight range for your height and gender. Enter your height in metric (cm) or imperial (ft/in) units, select your gender, and get results from four widely used medical formulas — Devine, Hamwi, Robinson, and Miller — alongside the WHO-recommended healthy BMI range (18.5–24.9).
No single formula defines "perfect" weight. These tools are reference points used in medicine for dosing calculations and nutritional assessment. Your ideal weight in practice depends on muscle mass, bone structure, and overall fitness — not just height and gender.
Frequently Asked Questions
What is ideal body weight?
Ideal body weight (IBW) is an estimated weight range considered optimal for a person's height and gender. It is commonly used in medicine to determine drug dosages and assess nutritional status. There is no single "perfect" number — IBW is a useful reference range, not a strict target.
What formulas does this calculator use?
The calculator uses four established medical formulas: Devine (1974), Hamwi (1964), Robinson (1983), and Miller (1983). All four were developed for adults and use height in inches above 5 feet as the key variable. The results differ slightly because each formula was derived from different population samples.
What is the difference between the BMI healthy range and the formula results?
The BMI-based range (18.5–24.9) gives the weight interval within which a person is considered to have a healthy body mass index. The four formulas calculate a single target weight per gender. In practice, both approaches give similar values, but the BMI range is broader and accounts for natural body variation.
Does gender affect ideal weight?
Yes. Women naturally have a higher percentage of body fat and a different body composition than men of the same height. All four formulas use a lower baseline weight for women, resulting in a lower ideal weight estimate compared to men of the same height.
What if my actual weight is above or below the ideal range?
Ideal weight is a reference guideline, not a strict health boundary. Many factors affect healthy weight: muscle mass, bone structure, age, and fitness level. If your weight differs significantly from the range, consult a doctor or registered dietitian — weight alone does not fully determine health status.
Which ideal weight formula is most commonly used in medicine?
The Devine formula (1974) is the most widely used in clinical settings, particularly for calculating drug dosages such as for chemotherapy and anesthesia. It was originally developed for men, with a modification for women. The other formulas (Hamwi, Robinson, Miller) were also widely used but are now mainly seen in nutritional and fitness contexts.
How much does height affect ideal weight?
Height is the primary driver of ideal weight in all four formulas. As a rough guide, each additional centimetre of height above 152 cm (5 ft) adds approximately 0.9–1.1 kg to the ideal weight for men, and 0.7–0.9 kg for women, depending on the formula used. Taller individuals have proportionally higher ideal weights.
What is the difference between ideal weight and healthy weight?
Ideal weight (from the four formulas) is a specific target value — a single number per gender and height. Healthy weight (from BMI 18.5–24.9) is a range. In practice, your healthy weight range is typically broader than the single ideal weight figure. Both are guidelines, not medical diagnoses.
Does age affect ideal weight calculations?
The four classic formulas do not adjust for age — they were developed primarily for adults aged 18–65. However, older adults (65+) tend to have less muscle mass and more body fat at the same weight. Some specialists suggest that a slightly higher body weight may be protective in elderly individuals, and waist circumference becomes a more relevant health marker.
Is my ideal weight the same as my goal weight?
Not necessarily. Your goal weight is a personal target based on how you feel, your fitness objectives, and health recommendations from your doctor. Your ideal weight (from formulas) is a statistical reference based on height and gender. For athletes with high muscle mass, the formula-based ideal weight may seem too low. Use ideal weight as a starting reference, then personalise with professional guidance.