Ideal body weight (IBW) is a medical and clinical concept used primarily by healthcare providers to estimate appropriate dosing for medications, adjust nutritional requirements, and set clinical targets. Unlike BMI, IBW formulas produce a single number rather than a range. However, most health professionals agree that a healthy weight range — rather than one specific number — is a more realistic and useful target for the general population. This guide explains the major IBW formulas, how they compare, and how to use them practically.