Ideal Weight
Healthy target weight from four clinical formulas (Devine, Robinson, Miller, Hamwi).
Ideal weight (average of formulas)
70 kg
Devine
70.5 kg
Robinson
68.9 kg
Miller
68.7 kg
Hamwi
72 kg
AI Breakdown & Smart Takeaway
Plain-English insight on your numbers
Get a personalized explanation of what these results mean — and how to improve them.
How the Ideal Weight works
The Ideal Weight Calculator estimates your healthy target weight using four widely-cited clinical formulas—Devine, Robinson, Miller, and Hamwi—so you can see a science-backed range rather than a single arbitrary number. It's useful for adults tracking fitness goals, healthcare providers doing quick assessments, or anyone curious about where their weight stands relative to established medical benchmarks.
This calculator applies four distinct formulas that physicians and researchers have used since the 1960s and 1970s, each developed for slightly different clinical contexts. The Devine formula, created by Dr. B.J. Devine in 1974 originally for pharmacological dosing, became the most widely adopted and remains a clinical standard today. Robinson, Miller, and Hamwi each offer alternative derivations that account for height increments differently, which is why the four results you see can vary by several pounds even for the same person. Presenting all four together gives you a clinically grounded range rather than a falsely precise single figure.
All four formulas are built on height as the primary input, with separate baseline values and per-inch increments for males and females assigned at birth. For example, the Devine formula sets a base weight of 50 kg for men and 45.5 kg for women at 5 feet, then adds 2.3 kg for every inch above that. The Robinson and Miller formulas use similar structures but with slightly different base weights and increment rates, reflecting the different populations each researcher studied. This is why your sex and height are the only required inputs—the formulas deliberately exclude age, muscle mass, and frame size to keep them fast and broadly applicable.
A key limitation worth understanding is that these formulas were derived from population data that skewed toward certain demographics and did not fully account for body composition. A highly muscular athlete may fall above the 'ideal' range without carrying excess fat, while a sedentary person could fall within it but still have an unfavorable fat-to-muscle ratio. Ideal weight estimates are best used as a starting reference point alongside other metrics like body fat percentage, waist circumference, or BMI—not as a standalone verdict on health.
A common mistake users make is treating the highest or lowest formula output as the target to chase, rather than recognizing the full range as the zone of healthy weight. Another pitfall is ignoring frame size: people with naturally larger bone structures may reasonably sit at the upper end of the range, while smaller-framed individuals may feel best at the lower end. Use the calculator's results to anchor a conversation with a healthcare provider, not to set a rigid number that ignores how you actually feel, perform, and function day to day.
Formula
Devine (men): 50 + 2.3 × (inches over 5 ft) kg
Pro tips
- Pair with BMI and Body Fat for a fuller picture than any single number.
Key terms
- Devine Formula
- — A 1974 clinical equation developed by Dr. B.J. Devine that calculates ideal body weight from height using a fixed base weight plus 2.3 kg per inch above 5 feet, originally created for drug dosing calculations.
- Ideal Body Weight (IBW)
- — A medically estimated target weight for a given height and sex, used as a reference for drug dosing, nutritional planning, and fitness goal-setting rather than as a strict definition of health.
- Hamwi Formula
- — An ideal weight equation developed by Dr. G.J. Hamwi in 1964 that uses slightly higher per-inch increments than Devine, often used in dietetic and nutritional practice.
- Robinson Formula
- — A 1983 revision of ideal weight estimation that applies lower per-inch increments than Devine, producing slightly lower target weights especially at taller heights.
- Body Composition
- — The proportion of fat mass versus lean mass (muscle, bone, water) in the body, which ideal weight formulas do not directly measure but which critically determines actual health outcomes.
- Frame Size
- — A subjective classification of a person's skeletal structure as small, medium, or large, which influences where within a healthy weight range an individual naturally and healthfully sits.
