Ideal body weight is used in clinical practice to calculate drug doses for medicines that distribute in lean tissue rather than fat — including some antibiotics, bronchodilators, and anaesthetic agents. The Devine formula was originally derived from insurance data and remains the most widely used method. Adjusted body weight is an intermediate value used when a patient's actual weight exceeds their ideal weight by more than 20%, as in certain obese patients receiving renally-cleared drugs.
This tool is for reference only. Clinical decisions should always involve a qualified healthcare professional.