BMI for 183 cm and 45 kg
A person 183 cm (6'0") tall weighing 45 kg (99 lbs) has a BMI of 13.4 — classified as Underweight. The healthy weight range for this height is 62.0–83.4 kg.
Your BMI score
Quick health screening — not a diagnosis
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
- YouSevere thinness< 16
- Underweight16 – 18.5
- Normal18.5 – 24.9
- Overweight25 – 29.9
- Obese I30 – 34.9
- Obese II35 – 39.9
- Obese III≥ 40
What does this BMI mean?
Severely underweight · BMI 13.4 · Underweight
13.4 sits in the severely-underweight band. For a 183 cm frame, that's roughly 17.0 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.
One number can't capture body composition. BMI is useful for population comparison and as a rough self-check, but pairing it with waist circumference or body-fat measurement gives a much more honest read.
For someone 183 cm tall, weights between 62.0 kg and 83.4 kg fall in the BMI 18.5–24.9 healthy range — roughly 137–184 lbs.
How far from the healthy range?
Target BMI milestones
Weights that would land at common BMI thresholds for 183 cm.
| Milestone | Target weight | vs current |
|---|---|---|
| BMI 18.5 (lower healthy bound) | 62.0 kg(137 lbs) | Gain ~17.0 kg |
| BMI 20 (low-healthy) | 67.0 kg(148 lbs) | Gain ~22.0 kg |
| BMI 22 (mid-healthy) | 73.7 kg(162 lbs) | Gain ~28.7 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