Pregnancy Weight Gain Calculator

Track healthy weight gain throughout pregnancy

Enter Your Details

BMI = weight (kg) ÷ height² (m²). Calculate your BMI →

Not sure of your weeks? Use the Due Date Calculator.

Medical Disclaimer: This tool is for educational and informational purposes only. It does not provide medical advice, diagnosis, or treatment. Results are estimates only. Always consult a qualified healthcare professional for medical decisions. In an emergency, call 995 (Singapore) immediately.

Recommended Weight Gain by Pre-Pregnancy BMI

IOM/ACOG guidelines for singleton pregnancies.

BMI Category Pre-preg BMI Total Gain 2nd/3rd Tri Rate
Underweight < 18.5 12.5–18 kg 0.5 kg/week
Normal weight 18.5–24.9 11.5–16 kg 0.4 kg/week
Overweight 25–29.9 7–11.5 kg 0.3 kg/week
Obese ≥ 30 5–9 kg 0.2 kg/week

For twin pregnancies, total gain is typically 5–7 kg higher. Always follow your obstetrician's individual guidance.

Where Does Pregnancy Weight Go?

Baby 3.2–3.8 kg
Placenta 0.7–0.8 kg
Amniotic fluid 0.8–1.0 kg
Uterus growth 0.9–1.0 kg
Blood volume increase 1.3–1.5 kg
Breast tissue 0.5–1.5 kg
Body fat stores 2.5–3.5 kg
Fluid retention 1.0–2.5 kg

Weight gain is essential for a healthy pregnancy. Very low weight gain is linked to preterm birth and low birth weight. For nutrition guidance, visit the Pregnancy Hub →

Get Weekly Baby & Pregnancy Tips

Join 50,000+ parents. Personalised advice, tool reminders, and the latest guides — straight to your inbox.

No spam. Unsubscribe anytime.