BMI for 173 cm and 50 kg

A person 173 cm (5'8") tall weighing 50 kg (110 lbs) has a BMI of 16.7 — classified as Underweight. The healthy weight range for this height is 55.474.5 kg.

Your BMI
16.7
Category
Underweight
Under 18.518.5–24.925–29.930+
Healthy weight range: 55.474.5 kg

Your BMI score

Quick health screening — not a diagnosis

Underweight
BMI gauge
BMI
16.7
Underweight

Your BMI suggests you may be under the recommended weight range.

What this means

BMI is a quick screening number based only on height and weight. It doesn't distinguish muscle from fat, and shouldn't replace a clinical assessment.

  • 18.5–24.9 generally lowest health risk
  • 25–29.9 elevated metabolic risk
  • 30+ higher long-term risk

BMI range

WHO adult classification

Your BMI: 16.7
121618.525303540+
  1. Severe thinness< 16
  2. Underweight16 – 18.5
    You
  3. Normal18.5 – 24.9
  4. Overweight25 – 29.9
  5. Obese I30 – 34.9
  6. Obese II35 – 39.9
  7. Obese III≥ 40
Lower riskModerateHigher risk

What does this BMI mean?

Underweight · BMI 16.7 · Underweight

A BMI of 16.7 is below the lower healthy bound of 18.5. For 173 cm, the healthy weight range starts at about 55.4 kg, so this result sits roughly 5.4 kg under that.

Being underweight isn't automatically a problem, but it can come with lower iron, B12, or calorie reserves. Worth investigating if weight has dropped without trying.

Treat this as a starting point, not a verdict. BMI ignores muscle mass, body shape, and individual context — it's a quick number for a population, not a personal health score.

For someone 173 cm tall, weights between 55.4 kg and 74.5 kg fall in the BMI 18.5–24.9 healthy range — roughly 122164 lbs.

How far from the healthy range?

Lower healthy bound
55.4 kg
122 lbs · BMI 18.5
Deficit
5.4 kg
12 lbs from the nearest bound
% below floor
9.7%
Relative to the BMI 18.5 cutoff

Target BMI milestones

Weights that would land at common BMI thresholds for 173 cm.

MilestoneTarget weightvs current
BMI 18.5 (lower healthy bound)55.4 kg(122 lbs)Gain ~5.4 kg
BMI 20 (low-healthy)59.9 kg(132 lbs)Gain ~9.9 kg
BMI 22 (mid-healthy)65.8 kg(145 lbs)Gain ~15.8 kg

Why BMI isn't the whole story

  • Muscle vs fat: BMI treats a kilogram of muscle the same as a kilogram of fat. Strength athletes and very muscular builds can land in the overweight band while having low body fat.
  • Body shape matters: Two people at the same BMI can carry weight very differently. Waist circumference and waist-to-height ratio capture risk that BMI misses.
  • Age, sex, ethnicity: The 18.5–24.9 window is a single global average. Cutoffs adjusted for ethnicity and age can shift the interpretation, especially at the edges of the band.
  • Still useful: BMI remains widely used because it's cheap, fast, and roughly predictive at population scale. Treat it as a self-check signal, not a diagnosis.

Nearby BMI combinations

Related

Common questions

Last updated: 2026