How to Calculate Target Weight from BMI
Target weight = goal BMI × height (m)². For example, a goal BMI of 22 at 5'7" (170 cm / 1.70 m) gives 22 × 1.7² = 63.5 kg. The difference between current and target weight, divided by a safe weekly change rate, gives your estimated timeline.
US BMI Classification (CDC)
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Nutritional risk |
| 18.5–24.9 | Normal weight | Low |
| 25.0–29.9 | Overweight | Moderately increased |
| 30.0–34.9 | Obese Class I | High |
| 35.0+ | Obese Class II | Very high |
Safe Rate of Weight Change
Losing 0.5 kg/week (about 1 lb/week) preserves muscle mass best. The maximum recommended rate is 1 kg/week. For weight gain (muscle building), 0.25–0.5 kg/week minimizes fat gain. Rapid changes in either direction risk muscle loss, metabolic adaptation, or health complications.
Frequently Asked Questions
BMI 22 falls within the normal range but optimal BMI varies by individual factors including age, sex, and ethnicity. Asian populations often use BMI 23 as the overweight threshold. Consult a doctor for personalized guidance.
Waist circumference (men: over 102 cm / 40 in is high risk; women: over 88 cm / 35 in), body fat percentage, and waist-to-hip ratio provide a more complete health picture alongside BMI.