What is Ideal Body Weight (IBW)?
Ideal Body Weight is a clinical estimate of how much an individual should weigh based on their height and gender. While it doesn't account for muscle mass or bone density perfectly, it provides a crucial baseline for dosage calculations in medicine and general health goal setting.
The Four Main Formulas
- Devine Formula: The clinical gold standard for medical dosing and lung protection.
- Robinson Formula: An improved version of Devine for better accuracy in modern populations.
- Miller Formula: Often provides the most conservative "lean" estimates.
- Hamwi Formula: Popular among nutritionists for its simplicity and frame-size flexibility.
Why a Healthy Range Matters
Health professionals usually look at the "Healthy Weight Range" corresponding to a **BMI of 18.5 to 24.9**. This allows for natural variations in:
Bone Structure
Heavier bones can add 2-4kg to your frame without increasing fat mass.
Muscle Density
Muscle is more compact than fat; active users may weigh more but be metabolically leaner.
Clinical Limitations
Ideal body weight formulas are primarily height-based. They do not distinguish between lean muscle mass and adipose tissue (fat). Consequently, these formulas may categorize athletes or bodybuilders as being "above ideal weight" despite having very low body fat and excellent metabolic health.
↗ Cross-Reference
For a more holistic health assessment, use:
Weight Targeting FAQ
Q: Is Ideal Weight accurate for athletes?
A: No. Formulas primarily use height and gender. Athletes with high muscle mass will often weigh significantly more than their "ideal" clinical weight while remaining healthy.
Q: Which formula should I trust most?
A: The Devine formula is the medical gold standard, while Robinson and Miller often provide better estimates for modern general populations.
Q: How does age affect my ideal weight?
A: These formulas don't account for age directly, but since BMR drops with age, maintaining a weight near the lower end of the IBW range becomes progressively harder.
Q: Is "Small frame" vs "Large frame" real?
A: Yes. Bone structure can vary weights by 5-10%. The Hamwi formula is often used by practitioners to adjust for frame size by adding or subtracting 10% from the result.
Clinical Reference
Standardized Clinical Formulas: Devine (1974), Robinson (1983)
Editorial Status
Last Updated: January 2026 | Reviewed for Clinical Consistency