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Pregnancy Weight Gain Calculator

Find your recommended weight gain range by trimester, based on Institute of Medicine guidelines and your pre-pregnancy BMI.

Your Details

kg
cm
wk
Total Recommended Gain
1st Trimester (weeks 1–13)
Weight gain is minimal in first trimester
2nd Trimester (weeks 14–27)
Main growth phase begins
3rd Trimester (weeks 28–40)
Baby gains most weight in this phase
By Week
Your expected gain at current week

Based on 2009 Institute of Medicine guidelines. Always follow your OB-GYN's personal recommendations.

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Your results will appear here

How Much Weight Should I Gain During Pregnancy?

The Institute of Medicine recommends different weight gain ranges based on pre-pregnancy BMI. Underweight women (BMI below 18.5) should gain 12.5–18 kg (28–40 lb). Normal weight women (18.5–24.9) should gain 11.5–16 kg (25–35 lb). Overweight women (25–29.9) should gain 7–11.5 kg (15–25 lb). Obese women (30+) should gain 5–9 kg (11–20 lb).

Why Healthy Weight Gain Matters

Gaining too little can lead to premature birth and low birth weight. Gaining too much increases risks of gestational diabetes, C-section, and postpartum weight retention. Both extremes affect long-term health for mother and child. Regular prenatal care with a healthcare provider is essential.