Pregnancy Weight Gain Calculator

See the recommended pregnancy weight-gain range for your pre-pregnancy BMI using IOM 2009 guidelines, for single or twin pregnancies. Free and private.

Independently verified for accuracy

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Pre-pregnancy BMI
22.04 (Normal weight)
Recommended total gain
25 to 35 lb

See how much weight is recommended during pregnancy based on your pre-pregnancy BMI, using the Institute of Medicine's 2009 guidelines. Enter your starting weight and height, choose a single baby or twins, and get the recommended total gain range in pounds.

How this is calculated

It computes your pre-pregnancy BMI (weight in kg divided by height in metres squared), maps it to a WHO category, then returns the IOM 2009 total recommended gestational weight-gain range for that category, with separate ranges for singleton and twin pregnancies.

How to use

  1. Enter your pre-pregnancy weight in kilograms and your height in centimetres.
  2. Choose a single baby or twins.
  3. Read your BMI category and the recommended total weight-gain range.

Examples

  • Normal weight, 60 kg, 165 cm, single: 25 to 35 lb
  • Overweight, 85 kg, 170 cm, single: 15 to 25 lb

FAQ

Where do these ranges come from?
They are the Institute of Medicine 2009 recommendations for gestational weight gain, grouped by pre-pregnancy BMI. They are the ranges most obstetric guidelines in the US follow.
Why is there no range for underweight twins?
The IOM did not set a twin-pregnancy target for underweight women because there was not enough evidence. If that is your situation, your provider will give you an individual goal.
Is this medical advice?
No. It is an estimate based on population guidelines. Your provider may recommend a different target based on your health, so use this as a starting point for that conversation.

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