Pregnancy Weight Gain Calculator
See how much weight gain is generally recommended during pregnancy based on your pre-pregnancy BMI, and where you are against the range for your current week.
Recommended total gain
| Week | Suggested gain (low) | Suggested gain (high) |
|---|
How to use the pregnancy weight gain calculator
- Enter your weight before pregnancy and your height to find your starting BMI category.
- Enter your current week, and your current weight if you want to compare.
- Choose twins if you are expecting twins; the guidelines differ.
How much weight should I gain?
The Institute of Medicine (now the National Academy of Medicine) guidelines, used by ACOG and the CDC, recommend a total gain of 28–40 lb if your pre-pregnancy BMI was under 18.5, 25–35 lb for a BMI of 18.5–24.9, 15–25 lb for 25–29.9, and 11–20 lb for 30 or higher, for a single baby.
Most gain happens after the first trimester. The first 13 weeks typically add only about 1–4.5 lb, followed by a fairly steady weekly rate. For twins, recommended totals are higher: about 37–54 lb for a normal BMI.
These are population guidelines. Your provider may recommend a different target based on your health, and weight can fluctuate week to week. This calculator gives general estimates for information only and is not medical advice. Always follow your doctor or midwife's advice.
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Frequently asked questions
How much weight should I gain in pregnancy?
25–35 lb for most people who start at a normal BMI with one baby; the range depends on your starting BMI.
How much weight is gained in the first trimester?
Typically about 1–4.5 lb (0.5–2 kg).
What about twins?
Higher: about 37–54 lb for a normal starting BMI, 31–50 lb if overweight and 25–42 lb if obese.
Is gaining outside the range dangerous?
Not necessarily, but talk with your provider; they consider your whole health picture.