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.

How to Use the Pregnancy Weight Gain Calculator

Track healthy weight gain throughout pregnancy

1. Enter

Add the details requested in the form. Use the most recent measurements, dates, or figures you have.

2. Review

Read the result together with the notes below it. Estimates are most useful when you compare them with your own context.

3. Act

Save the result, try a related tool, or speak with a doctor, lactation consultant, childcare provider, or financial adviser when needed.

Singapore note: bring important pregnancy results to your antenatal visits at KKH, NUH, SGH, or your private obstetrician so your care team can interpret them clinically.

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 →

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