BMI for 209 cm and 55 kg

A person 209 cm (6'10") tall weighing 55 kg (121 lbs) has a BMI of 12.6 — classified as Underweight. The healthy weight range for this height is 80.8108.8 kg.

Your BMI
12.6
Category
Underweight
Under 18.518.5–24.925–29.930+
Healthy weight range: 80.8108.8 kg

Your BMI score

Quick health screening — not a diagnosis

Severe thinness
BMI gauge
BMI
12.6
Severe thinness

Your BMI is well below the healthy range and may indicate serious health risk.

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: 12.6
121618.525303540+
  1. Severe thinness< 16
    You
  2. Underweight16 – 18.5
  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?

Severely underweight · BMI 12.6 · Underweight

12.6 sits in the severely-underweight band. For a 209 cm frame, that's roughly 25.8 kg below where the healthy range starts.

Sustained low BMI can be linked to nutritional gaps, reduced bone density, or low energy. If the result is unintentional, a clinician check-up and basic blood work are sensible next steps.

BMI is a screening tool, not a diagnosis. It doesn't know the difference between fat and muscle, doesn't measure where weight sits on the body, and doesn't account for age, sex, or ethnicity-specific cutoffs.

For someone 209 cm tall, weights between 80.8 kg and 108.8 kg fall in the BMI 18.5–24.9 healthy range — roughly 178240 lbs.

How far from the healthy range?

Lower healthy bound
80.8 kg
178 lbs · BMI 18.5
Deficit
25.8 kg
57 lbs from the nearest bound
% below floor
31.9%
Relative to the BMI 18.5 cutoff

Target BMI milestones

Weights that would land at common BMI thresholds for 209 cm.

MilestoneTarget weightvs current
BMI 18.5 (lower healthy bound)80.8 kg(178 lbs)Gain ~25.8 kg
BMI 20 (low-healthy)87.4 kg(193 lbs)Gain ~32.4 kg
BMI 22 (mid-healthy)96.1 kg(212 lbs)Gain ~41.1 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