Pregnancy Weight Gain Calculator- Estimate Your Weekly Weight

How much weight should I gain or lose during pregnancy? This might be on your mind when your OB/GYN tells you to put on or lose some weight. You need to maintain the ideal recommended weight gain during pregnancy to avoid any pregnancy weight related complications.

MomJunction’s pregnancy weight gain calculator helps you in tracking your weight gain for each week of your pregnancy.

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If you are underweight or unable to gain the desired weight, it could affect the baby’s health and result in preterm labor. And, if you are overweight or obese, or gain weight excessively, it will affect both you and the baby causing complications in labor, C-section or a miscarriage.

You need to track your pregnancy weight and check the progress using pregnancy weight gain tracker based on height and weight before pregnancy to find out if you are under safe ranges of weight gain or not.

How Much Weight You Can Gain During Pregnancy ?

Appropriate weight gain during the weeks or trimesters of pregnancy depends on certain factors such as pre-pregnancy weight and BMI, whether you are carrying twins or multiples and more. Here is the general weight gain chart during pregnancy for recommended weight gain.

BMI Chart For Singleton Pregnancy Weight Gain

Pre-pregnancy BMI Category Recommended Weight Gain
< 18.5 Underweight 28-40lb (13-18kg)
18.5 – 24.9 Normal 24-35lb (11-16kg)
25-29.9 Overweight 15-25lb (7-11kg)
> 30 Obese 11-20lb (5-9kg)

BMI Chart For Twin Pregnancy Weight Gain

If you are carrying twins, you need to gain weight accordingly. Here is the general pregnancy weight gain chart for twins.

Pre-pregnancy BMI Category Recommended Weight Gain
18.5-24.9 Normal 28-40lb (13-18kg)
18.5 – 24.9 Normal 37-54lb (17-25kg)
25-29.9 Overweight 31-50lb (14-23kg)
> 30 Obese 25-42lb (11-19kg)

If you are carrying multiples or more, there are no set guidelines for pregnancy weight gain due to insufficient data. You should talk to your OB/GYN on how to gain the right weight.

When Do You Start Gaining Weight During Pregnancy ?

You will start to gain weight during the first trimester (due to retained water), but that is minimal. In the first month of pregnancy, there is little or no weight gain as the baby is just a tiny ball of cells. In fact, you might lose weight due to morning sickness in the initial months. Most women put on about 1.6kg in the first trimester.

During the second trimester, you will have the highest weight gain since your eating habits influence the baby’s weight. You will put around 0.5kg every week, totaling 5.5 to 6.4kg in that trimester. There will again be a considerable increase in weight during the third trimester, and it may slow down in the last month (due to food aversions or having an active baby). You will be gaining around 5kg in the last trimester. That is, normal weight gain during pregnancy should varies from 10 kg to 15 kg but again it depends on BMI ranges.


Our pregnancy weight calculator provides just an estimation. You need to discuss your weight issues with a medical practitioner before taking any measures. MomJunction is not liable for any related issues, consequences or damages.