Pregnancy Weight Gain Calculator
See your recommended pregnancy weight gain range by week, based on pre-pregnancy BMI and IOM 2009 guidelines, with weekly pace tracking.
Your pregnancy
Updates as you typeMode
What do you want to see? ?
Target total gain ?
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kg
Pre-pregnancy body
Height ?
cm
Pre-pregnancy weight ?
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kg
Pregnancy
Current week ?
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of 40
Current weight ?
kg
Carrying ?
Triplets+ have no published IOM range. Your provider will set a personalized target — the figures below mirror twins as a rough upper bound.
Gain over time
Recommended range shaded · your current position marked
Recommended range
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BMI categories & recommended gain
Institute of Medicine (IOM) 2009| Pre-pregnancy BMI | Category | Singleton total gain | Twins total gain | Weekly rate (2nd & 3rd tri) |
|---|---|---|---|---|
| Under 18.5 | Underweight | 12.5–18 kg (28–40 lbs) | 22.5–28 kg (50–62 lbs) | 0.45–0.59 kg (1.0–1.3 lbs) |
| 18.5–24.9 | Normal weight | 11.5–16 kg (25–35 lbs) | 17–25 kg (37–54 lbs) | 0.36–0.45 kg (0.8–1.0 lbs) |
| 25.0–29.9 | Overweight | 7–11.5 kg (15–25 lbs) | 14–23 kg (31–50 lbs) | 0.23–0.32 kg (0.5–0.7 lbs) |
| 30.0 and over | Obese | 5–9 kg (11–20 lbs) | 11–19 kg (25–42 lbs) | 0.18–0.27 kg (0.4–0.6 lbs) |
Talk to your provider
These ranges are general IOM guidance. Contact your prenatal care provider if you notice any of the following:
- Sudden weight gain of more than 1 kg (2 lb) in a week, especially with swelling or headaches (possible preeclampsia)
- Weight loss in the second or third trimester
- No weight gain for 2+ weeks after week 20
- Persistent nausea preventing you from eating
- Pre-existing conditions (diabetes, thyroid, eating disorder history) — your target may differ