1. What is the Hamwi Formula?

The Hamwi formula is a method to estimate ideal body weight based on height, with different equations for men and women. For women, the formula is: IBW (kg) = 45.5 + 2.3 × [height (inches) − 60].

2. How Does the Calculator Work?

The calculator uses the Hamwi formula for women:

Where:

• \( height \) — Height in inches
• 45.5 — Base weight in kg for a woman 5 feet tall
• 2.3 — Weight increment per additional inch above 5 feet

BMI Calculation: If weight is provided, the calculator also computes BMI using weight(kg)/height(m)².

3. Importance of IBW and BMI

Details: Ideal body weight helps determine appropriate weight for height, while BMI categorizes weight status (underweight, normal, overweight, obese).

4. Using the Calculator

Tips: Enter height in inches (1 foot = 12 inches). For BMI calculation, also enter current weight in kg. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between IBW and BMI?
A: IBW estimates healthy weight for height, while BMI assesses weight relative to height for population-level categorization.

Q2: Are there limitations to the Hamwi formula?
A: It doesn't account for frame size, muscle mass, or body composition. Other formulas (Devine, Robinson) may give slightly different results.

Q3: What are normal BMI values?
A: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q4: How accurate is IBW for athletic individuals?
A: Less accurate as it doesn't distinguish between muscle and fat. Body composition analysis may be better.

Q5: Should IBW be used for medication dosing?
A: Sometimes, but adjusted body weight may be more appropriate for obese patients.