Ideal Body Weight Guide

Why Multiple Formulas Exist

Ideal body weight (IBW) formulas were developed for clinical use — primarily to calculate drug doses for patients where weight-based dosing is needed but actual weight may be significantly above or below ideal. The Devine formula (1974) was originally developed for digoxin dosing. The Hamwi formula is widely used by dietitians. The Robinson (1983) and Miller (1983) formulas use slightly different coefficients. All are based on height and sex only — they do not account for frame size, age, or bod

IBW vs BMI Healthy Weight Range

The IBW formulas generally produce results in the middle of the healthy BMI range (18.5–24.9), not at the upper end. The BMI-based healthy range (18.5–24.9) is broader and generally more useful for individuals. IBW formulas are most appropriate in clinical settings for drug dosing — they should not be used as personal weight loss targets without considering individual factors like muscle mass, bone density, and age. An athletic person may be significantly above calculated IBW while being extreme

Frame Size Adjustment

Frame size (small, medium, large) can adjust ideal weight estimates by 10–15%. A simple test: measure wrist circumference. For women: small frame under 14cm, medium 14–16cm, large over 16cm. For men: small under 16cm, medium 16–19cm, large over 19cm. Alternatively, circle your wrist with opposite thumb and middle finger — if they overlap, small frame; if they meet, medium; if they do not meet, large frame.

Limitations and Context

No single number is the 'right' weight for everyone at a given height. IBW calculations are averages derived from population studies in specific demographics (primarily young, white, Western populations). They consistently underestimate ideal weight for Black, Asian, and other ethnic groups who may have different body composition profiles. For personal health goals, aim for a weight where you feel energetic, fit into a healthy BMI range, and have no weight-related health markers (blood pressure,

Not medical advice. This calculator is for general information and education only. Figures are estimates and may not reflect your circumstances. For decisions, consult your GP or a qualified healthcare professional. See our editorial standards.

Ideal Body Weight Calculator

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