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🀰 Pregnancy Weight Gain Calculator

Shows the recommended total pregnancy weight gain range from the US IOM guidelines based on your pre-pregnancy BMI.

ℹ️ This calculator assumes a singleton pregnancy. Twin and multiple pregnancies have different recommended ranges and are not supported.

Recommended total weight gain
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Pre-pregnancy BMI β€” β€”

⚠️ This result is reference information based on US IOM guidelines β€” it is not a medical diagnosis or prescription. Always discuss pregnancy weight management with your doctor.

Related tools BMI Ideal Weight ANC
GUIDE

Learn more

01

Recommended weight gain by BMI (IOM guidelines)

The 2009 guidelines from the US Institute of Medicine (IOM, now NAM) recommend the following total weight gain for singleton pregnancies by pre-pregnancy BMI: Underweight (BMI < 18.5): 12.5–18 kg (28–40 lb), Normal (18.5–24.9): 11.5–16 kg (25–35 lb), Overweight (25–29.9): 7–11.5 kg (15–25 lb), Obese (β‰₯ 30): 5–9 kg (11–20 lb). The lower your pre-pregnancy weight, the more gain is recommended, and vice versa. These ranges are statistical recommendations derived from maternal and fetal health outcomes.
02

Why pregnancy weight management matters

Gaining well below the recommended range is associated with a higher risk of low birth weight, while gaining well above it is associated with higher risks of gestational diabetes, hypertension, difficult delivery, and postpartum weight retention. The right target still depends on your individual health and how the pregnancy progresses β€” use this calculator only as a starting point and set goals with your doctor at regular prenatal visits.

Frequently asked questions

Do these ranges apply to twin pregnancies?
No. This calculator is for singleton pregnancies only. Multiple pregnancies have larger recommended ranges under separate guidelines β€” consult your doctor.
How is the gain distributed across trimesters?
Typically only 0.5–2 kg is gained in the first trimester (weeks 1–13), with steady weekly gain in the second and third trimesters (about 0.35–0.5 kg per week for a normal BMI). Set per-stage targets with your doctor.
What if I am outside the recommended range?
Do not drastically change your diet on your own β€” dieting during pregnancy can be dangerous. If you are concerned about your weight trend, raise it with your doctor at your next prenatal visit first.