Which formula is used to calculate ideal body weight (IBW)?

The formula for calculating ideal body weight (IBW) for adults is typically based on a standard framework that considers height and adjusts for gender. The formula you mentioned—50 kg plus an additional 2.5 kg (or approximately 5 lbs) for every inch over 5 feet—provides a straightforward method to estimate the ideal body weight for individuals.

Using the correct formula allows healthcare professionals to assess a patient's nutritional status and suitability for certain medical interventions, such as dosing of medications or mechanical ventilation settings. The reference starting point of 50 kg represents the ideal weight for a 5-foot tall individual, and the addition of 2.5 kg for each inch above this height accounts for increases in lean body mass, which is significant in evaluating overall health.

This method effectively establishes a baseline that can then be adjusted based on factors such as body composition, age, and sex, but it provides a useful approximation for most adults. The other options either use different starting points or adjustment values that do not align with the standard calculations for IBW, making them less accurate for determining ideal body weight in a medical context.