🤰 Pregnancy Weight Gain Calculator
Calculate recommended total pregnancy weight gain and weekly gain targets based on ACOG/IOM guidelines, your pre-pregnancy BMI, and current gestational week.
ACOG/IOM Recommended Pregnancy Weight Gain
| Pre-pregnancy BMI | Category | Total Gain | Rate (wk 14+) |
|---|---|---|---|
| < 18.5 | Underweight | 12.5–18 kg | 0.5–0.6 kg/wk |
| 18.5–24.9 | Normal weight | 11.5–16 kg | 0.4–0.5 kg/wk |
| 25.0–29.9 | Overweight | 7–11.5 kg | 0.2–0.3 kg/wk |
| ≥ 30.0 | Obese | 5–9 kg | 0.2–0.3 kg/wk |
Frequently Asked Questions
Your pre-pregnancy BMI determines how much weight is appropriate to gain during pregnancy. Underweight women need to gain more to support fetal growth; overweight and obese women should gain less to minimise risks of gestational diabetes, hypertension, and large-for-gestational-age babies.
Excessive gestational weight gain increases risks of gestational diabetes, caesarean delivery, postpartum weight retention, and delivering a large baby (macrosomia). It can also increase the child's long-term risk of obesity.
Insufficient weight gain is associated with preterm birth, low birth weight, intrauterine growth restriction (IUGR), and feeding difficulties. Underweight women are at higher risk and generally need to gain at the upper end of recommendations.
In the first trimester (weeks 1–13), weight gain is usually minimal — roughly 0.5–2 kg total. The majority of pregnancy weight gain occurs in the second and third trimesters as the baby grows.
Weight loss is not recommended during pregnancy. Even obese women should gain some weight (at least 5 kg) to support fetal development. Speak with your healthcare provider or midwife about personalised advice.
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