Pregnancy Weight Gain Calculator
Calculate recommended pregnancy weight gain based on your pre-pregnancy BMI and current week of pregnancy.
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Recommended Weight Gain
Pregnancy weight gain recommendations are based on pre-pregnancy BMI, according to the Institute of Medicine (IOM) guidelines.
Recommended total weight gain by BMI category:
| Pre-Pregnancy BMI | Category | Recommended Gain |
|---|---|---|
| Below 18.5 | Underweight | 28–40 lbs (12.5–18 kg) |
| 18.5–24.9 | Normal weight | 25–35 lbs (11.5–16 kg) |
| 25.0–29.9 | Overweight | 15–25 lbs (7–11.5 kg) |
| 30.0+ | Obese | 11–20 lbs (5–9 kg) |
Typical weight gain pattern:
- First trimester (weeks 1–12): 1–4.5 lbs total
- Second trimester (weeks 13–26): About 1 lb/week
- Third trimester (weeks 27–40): About 1 lb/week
Where the weight goes:
- Baby: 7–8 lbs
- Placenta: 1–2 lbs
- Amniotic fluid: 2 lbs
- Uterus growth: 2 lbs
- Breast tissue: 2 lbs
- Blood volume increase: 4 lbs
- Fat stores: 5–9 lbs
- Fluid retention: 4 lbs
Important: Every pregnancy is different. Always follow your healthcare provider’s personalized recommendations.