Pregnancy Weight Gain Calculator

Profile view of a pregnant woman showing the baby in her womb

The Pregnancy Weight Gain Calculator will help you determine the recommended weight gain that will promote a healthy pregnancy.

What are the benefits of gaining a healthy amount of weight during pregnancy?

Gaining a healthy amount of weight during pregnancy can:

  • help your baby have a healthy start;
  • reduce your risk of complications in pregnancy and at delivery; and
  • improve your long-term health.

Recommended weight gain is based on a woman's Body Mass Index before pregnancy (her pre-pregnancy BMI).

Calculate your pre-pregnancy BMI

Enter your weight before your pregnancy:

  • or

Enter your height:

  • or

  • and

Based on your pre-pregnancy BMI, your recommended weight gain is between:
12.5 - 18 kg (or 28 -40 lbs)

Pre-pregnancy BMI under 18.5
Text Equivalent

This is the Gestational Weight Gain Monitoring Chart for underweight. This graphic shows the appropriate range of rate of gain per week for a woman with a pre-pregnancy BMI under 18.5. The rate shown is 0.44 to 0.58 kg (1.0 to 1.3 pound) per week in the 2nd and 3rd trimester. Trimester is shown on the x-axis and weight gain is shown on the y-axis. The total weight gain recommended is between 12.5 - 18 kg (or 28 -40 lbs).

The above recommended weight gain can be used as a general guide for single pregnancies. The Pregnancy Weight Gain Calculator should not replace individualized medical advice.

Print this page and check with your health care provider to make sure this amount of weight gain is right for you.

When will you gain the weight?

  • Most women can expect to gain about 1 to 2 kg (about 2 to 4 lbs) in the first trimester.
  • Most weight gain happens gradually during the second and third trimesters. However, a sudden peak in the rate of weight gain during the second trimester is not unusual.

What can you do to gain a healthy amount of weight during pregnancy?

  • Talk to your health care provider early in your pregnancy about what you can expect and to set a weight gain goal.
  • Eat "twice as healthy", not "twice as much". In most cases, just a little more food is enough. Follow the recommendations in Canada's Food Guide.
  • Add up activities in periods of at least 10 minutes, for a total of 30 minutes of activity each day.
  • Activities such as walking, gardening, housework, and swimming can be done safely during pregnancy.
  • Talk to your health care provider before increasing your activity level or before starting an exercise program.

Additional Resources

Related Resources

Physical activity:

Healthy Pregnancy:

Report a problem on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, please contact us.

Date modified: