Overview

Calculate the recommended weight gain during pregnancy based on your pre-pregnancy BMI. This calculator follows the 2009 Institute of Medicine (IOM, now National Academies) guidelines and provides recommendations for both singleton and multiple pregnancies. Individual needs may vary, so consult your healthcare provider.

Formula

Pre-pregnancy BMI = Weight (kg) / Height (m)^2

IOM Recommended Total Weight Gain (singleton):
- Underweight (BMI < 18.5): 12.5 – 18.0 kg (28 – 40 lbs)
- Normal weight (BMI 18.5–24.9): 11.5 – 16.0 kg (25 – 35 lbs)
- Overweight (BMI 25.0–29.9): 7.0 – 11.5 kg (15 – 25 lbs)
- Obese (BMI >= 30.0): 5.0 – 9.0 kg (11 – 20 lbs)

How to Use

1. 1Enter your pre-pregnancy weight (kg) and height (cm).
2. 2Enter your current gestational week.
3. 3Enter your current weight.
4. 4Click the 'Calculate' button.
5. 5Your BMI classification, recommended total gain, recommended range for your current week, and comparison with actual gain will be displayed.

Tips

• ✔A gain of 0.5–2 kg in the first trimester is typical, followed by about 0.4–0.5 kg per week in the second and third trimesters.
• ✔Excessive weight gain increases the risk of gestational diabetes, preeclampsia, and macrosomia (large baby).
• ✔Insufficient weight gain may raise the risk of preterm birth and low birth weight.
• ✔Twin or multiple pregnancies require higher weight gain targets — discuss with your doctor.
• ✔This calculator provides general guidelines; your doctor's personalized recommendation takes precedence.

FAQ