Pregnancy Weight Calculator

Each pregnancy is unique, and weight gain may vary between women, and even between pregnancies. Try not to worry too much abour weight gain, and instead focus on eating a healthy, balanced diet rich in fresh fruits and vegetables.

This calculator takes into account your height, weight and age to give you a general idea of how much weight you are expected to gain during pregnancy.

Teen Mother
Expecting Twins
Pre-pregnancy BMI

Total Pounds Expected weight gain during pregnancy.

Week Gain Weight Gain Weight Gain Weight

This information is not intended to replace the advice of a trained medical doctor. Health & Parenting LTD disclaims any liability for the decisions you make based on this information, which is provided to you on a general information basis only and not as a substitute for personalized medical advice.

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The calculations use your pre-pregnancy BMI to determine your weight gain goal. If you have a:

  • BMI of less than 19 you will be advised to gain between 13 and 18kg (28 to 40lb).
  • Normal BMI (between 19 and 24) you should expect to gain between 11 and 16kg (25 to 35lb).
  • BMI of 24.5 to 29.5 you should aim to gain between 7 and 11kg (15 to 25lb).
  • BMI of 30 or more you should aim to gain 5 to 9kg (11 to 20lb).

If you are carrying multiples, you should expect to gain extra. For twins, it could be an extra 4.5kg (10lb) by the end of the pregnancy, and this amount could increase for triplets or more.

Where does the weight go?

Maternal stores of nutrients and muscle development 7
Increased body fluid 4
Increased blood 3 – 4
Breast growth 1 – 2
Enlarged uterus 3 – 4
Amniotic fluid 1 – 2
Placentia 3 – 4
Baby 6 – 8
Total 26.5 – 30.5
Source: American College of Obstetricians and Gynecologists

If your pre-pregnancy BMI was between 19 and 24, you may put on around 2kg (4lb) during the first trimester. In the second and third trimesters, you may gain as much as 0.5kg (1lb) a week, though this will decrease to just 0.5-1kg (1-2lb) during the final month of the pregnancy.

If you are worried about your weight gain, please speak to your healthcare provider.