BMI for BMI for 165cm, 49kg is 18 — Underweight
A BMI of 18 falls in the Underweight range. The ideal weight range for this height is 50–68kg (110–150lbs).
▶ Open full BMI calculatorWhat a BMI of 18 means
A BMI of 18 is below the healthy range. Being underweight can be associated with nutritional deficiencies and reduced immune function. Reaching the healthy range would mean gaining approximately 1kg.
BMI is a screening tool, not a diagnostic measure. It doesn't account for muscle mass — a muscular athlete may have a high BMI despite low body fat. For a more complete picture, combine BMI with your body fat percentage. The estimated body fat for this BMI is approximately 12% (Deurenberg formula, assumes male aged 30 — use the body fat calculator for personalised results).
The WHO healthy BMI range (18.5–24.9) applies to adults of all ethnicities, though some health bodies recommend lower thresholds for people of Asian descent. Always discuss your results with a qualified healthcare provider.
Frequently asked questions
Is a BMI of 18 healthy?+
A BMI of 18 is classified as Underweight. The healthy BMI range is 18.5–24.9. To reach the healthy range, approximately 1kg would need to be gained.
What is the ideal weight for 165cm?+
For a height of 165cm, the healthy weight range (BMI 18.5–24.9) is 50–68kg (110–150lbs). This range is associated with the lowest health risk according to WHO standards. Note that "ideal" weight varies by individual — muscle mass, bone density, age, and ethnicity all affect what's healthy for a specific person.
How accurate is BMI?+
BMI is a useful population-level screening tool but has individual limitations. It doesn't distinguish between fat and muscle mass — a muscular person may have a high BMI despite having low body fat. It also doesn't account for fat distribution (abdominal fat is more associated with health risk than overall BMI). Use BMI alongside waist circumference and body fat percentage for a more complete picture.