Ideal Weight by Height
"What should I weigh for my height?" has two honest answers: a range (the modern, BMI-based answer) and a single number (the old clinical formulas still used for drug dosing). They usually land in the same neighbourhood, and the differences between them tell you something useful about how loose "ideal" really is.
The range answer: BMI 18.5–24.9
Current health guidance defines a healthy weight as any weight that puts BMI between 18.5 and 24.9 — deliberately a band, not a point, because bodies with different builds are healthy at different weights. The window is wide: about 20 kg (45 lb) for an average-height adult.
| Height | Healthy range (kg) | Healthy range (lb) |
|---|---|---|
| 150 cm (4′11″) | 41.6 – 56.0 | 92 – 124 |
| 155 cm (5′1″) | 44.4 – 59.8 | 98 – 132 |
| 160 cm (5′3″) | 47.4 – 63.7 | 104 – 141 |
| 165 cm (5′5″) | 50.4 – 67.8 | 111 – 149 |
| 170 cm (5′7″) | 53.5 – 72.0 | 118 – 159 |
| 175 cm (5′9″) | 56.7 – 76.3 | 125 – 168 |
| 180 cm (5′11″) | 59.9 – 80.7 | 132 – 178 |
| 185 cm (6′1″) | 63.3 – 85.2 | 140 – 188 |
| 190 cm (6′3″) | 66.8 – 89.9 | 147 – 198 |
The full 145–195 cm table is on the BMI chart page, and the calculator pinpoints where you sit inside the band.
The single-number answer: the classic formulas
Before BMI took over, clinicians estimated "ideal body weight" with height-based formulas. Three are still in use — notably the Devine formula, which remains standard for dosing certain medications:
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg per inch over 5 ft | 45.5 kg + 2.3 kg per inch over 5 ft |
| Robinson (1983) | 52 kg + 1.9 kg per inch over 5 ft | 49 kg + 1.7 kg per inch over 5 ft |
| Hamwi (1964) | 48 kg + 2.7 kg per inch over 5 ft | 45.5 kg + 2.2 kg per inch over 5 ft |
Worked example — a 175 cm (5′9″) man:
- Devine: 50 + 2.3 × 9 = 70.7 kg
- Robinson: 52 + 1.9 × 9 = 69.1 kg
- Hamwi: 48 + 2.7 × 9 = 72.3 kg
- BMI healthy range at 175 cm: 56.7 – 76.3 kg
All three formulas land comfortably inside the BMI band — around BMI 22–23.5. That is not a coincidence; the middle of the BMI range is roughly where the old "ideal" always was.
Which should you use?
- For health decisions: the BMI range, adjusted for what BMI cannot see — muscle (see athletes), age (see BMI by age) and ancestry (see Asian cut-offs).
- For a personal target: pick a weight inside the band that matches your build and is maintainable — for most people the practical sweet spot is BMI 21–24. A target of "BMI 20" is not more virtuous than "BMI 24"; sustainability beats the number.
- The formulas are best treated as historical reference points — or trivia to understand why your pharmacist cares about your height.
Bottom line
There is no single ideal weight, and the tools agree on this more than they disagree: for your height there is a ~20 kg healthy window, the classic formulas point at its middle, and where you should sit inside it depends on build, age and what you can maintain.