1. What is the Hamwi Formula?

The Hamwi formula is a method to estimate ideal body weight based on height and gender. It was developed by Dr. GJ Hamwi in 1964 and is commonly used in clinical settings for medication dosing and nutritional assessment.

2. How Does the Calculator Work?

The calculator uses the Hamwi equation:

Where:

• 50 kg — Base weight for males at 5 feet (60 inches)
• 45.5 kg — Base weight for females at 5 feet (60 inches)
• 2.3 kg — Weight added per inch over 5 feet

Explanation: The formula provides an estimate of ideal weight based on frame size, with different baselines for men and women.

3. Importance of Ideal Body Weight

Details: IBW is used for drug dosing calculations, nutritional assessment, and as a reference point for determining weight status. It's particularly important for medications with narrow therapeutic windows.

4. Using the Calculator

Tips: Enter height in feet and inches, select gender. The calculator will compute ideal body weight in kilograms based on the Hamwi formula.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the Hamwi formula?
A: It provides a reasonable estimate for average frame sizes but may not be accurate for very muscular or petite individuals.

Q2: What about for heights under 5 feet?
A: The formula uses the base weight (50kg male/45.5kg female) for heights ≤60 inches.

Q3: Are there other IBW formulas?
A: Yes, other methods include Devine, Robinson, and Miller formulas, each with slightly different coefficients.

Q4: How does IBW relate to BMI?
A: IBW typically corresponds to a BMI of about 21.5-22 for men and 20.5-21 for women.

Q5: When should IBW not be used?
A: For amputees, pregnant women, or highly muscular individuals, adjusted body weight formulas may be more appropriate.