What does a BMI of 20.9 mean at 4'10"?
According to the WHO/NHS standard BMI classification, a Body Mass Index of 20.9 is in the Normal weight band. At a height of 4'10" (about 147 cm), the official healthy weight range is 40.2–54 kg (88.6–119 lbs, or roughly 6 st 5 lb to 8 st 7 lb).
A weight of 100 lbs (45.4 kg) is within the healthy NHS-recommended weight range.
You are at the lowest statistical risk of weight-related health conditions such as type 2 diabetes, heart disease, and high blood pressure. Aim to maintain weight stability through balanced eating and regular activity.
Key facts
- BMI is a screening tool, not a diagnosis. It works well for most adults but does not distinguish between muscle and fat.
- If you are very muscular or athletic, your BMI may overestimate body fat. Pair this result with a body fat percentage check.
- For South Asian, Chinese, or Black ethnic groups, NICE recommends lower thresholds (overweight at BMI 23, obese at BMI 27.5).
- For pregnancy, use our pregnancy BMI calculator with pre-pregnancy weight instead.
- For children and teens, use the child BMI calculator with age-and-sex percentile bands.