How to Calculate Your Ideal Weight by Height: Formulas

Ideal weight is the weight range that matches your height and supports good health. Knowing it helps you manage your weight correctly.

Method 1: BMI

BMI = weight (kg) ÷ height (m)²

Asian/Thai standards:

BMI	Category
Below 18.5	Underweight
18.5 – 22.9	Normal (ideal)
23 – 24.9	Overweight
25+	Obese

Example: 170 cm, 65 kg → BMI = 65 ÷ (1.7)² = 22.5 → Normal

Method 2: Ideal Weight Formula (Lorentz)

• Men: ideal weight = (height cm − 100) − [(height − 150) ÷ 4]
• Women: ideal weight = (height cm − 100) − [(height − 150) ÷ 2]

Example: man, 170 cm → (170 − 100) − (20 ÷ 4) = 70 − 5 = 65 kg

Where It Applies

• Annual health checkups
• Weight loss/gain planning
• Comparing against medical standards

Try the ideal weight calculator to know your number instantly.