BMI 158 cm / 45 kg

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Your Height

Your Weight

Your BMI position: 18.0 — Underweight (WHO)

severe

under

normal

over

obese

Your BMI Result

18.0 kg/m² Underweight

How your BMI was calculated

Formula: BMI = weight (kg) ÷ height (m)²

Your values: 45 kg ÷ (1.58 m)²

Height squared: (1.58)² = 2.4964 m²

Result: 45 ÷ 2.4964 = 18.0 kg/m²

⚖️ Ideal Weight Range

46.2 kg — 62.2 kg

For 1.58 m height (BMI 18.5-24.9)

🎯 Weight Goal

↑ Gain 1.2 kg

Target: 46.2 kg to reach healthy BMI

What does a BMI of 18.0 mean?

Your BMI of 18.0 kg/m² indicates you are underweight.

At 1.58 m (158 cm) and 45 kg, your weight is below the healthy range of 18.5-24.9. Being underweight can affect your immune system, bone health, and energy levels.

Recommended actions:

Aim for a target weight of 46.2-62.2 kg
Increase calorie intake with healthy, nutrient-rich foods
Include protein and strength exercises to build muscle
Consult a doctor if you're having difficulty gaining weight

Remember: BMI is a screening tool, not a diagnostic measure. It doesn't account for muscle mass, bone density, or where fat is distributed. Always consult healthcare professionals for personalized health advice.

How weight changes affect your BMI

See how gaining or losing a few kilograms would change your BMI category:

Weight	BMI	Category
41 kg -4	16.4	Underweight
43 kg -2	17.2	Underweight
45 kg ← you	18.0	Underweight
47 kg +2	18.8	Normal
49 kg +4	19.6	Normal

This table shows how your BMI would change with different weights at your current height of 1.58 m.

BMI 18.0 (Underweight) — 158 cm / 45 kg — conversion chart

This BMI calculator is provided for informational purposes only and does not replace professional medical advice. Learn more about BMI, limitations, and health recommendations.

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