Pregnancy Weight Calculator: Here’s What to Know

As your baby grows, you will put on more pregnancy weight. But you want to make sure that your weight gain falls within the norms to keep you and the baby healthy. Your doctor will keep tabs on your weight gain to ensure that you are on track at every step of your pregnancy.

The American College of Obstetricians and Gynecologists has a guide for the expected weight gain based on your original body mass index (BMI):

• Underweight: BMI less than 18.5, expect to gain 28-40 pounds or 1-1.3 pounds per week
• Normal weight: BMI between 18.5-24.9, expect to gain 25-35 pounds or 0.8-1 pound per week
• Overweight: BMI between 25-29.9, expect to gain 15-25 pounds or 0.5-0.7 pounds per week
• Obese: BMI over 30, expect to gain 11-20 pounds or 0.4-0.6 pounds per week.

As you can see with these estimates, the higher your BMI, the less weight you’re expected to gain per week in the second and third trimesters. These calculations do assume that women gained between 1.1 and 4.4 pounds in the first trimester.

Each woman is different when it comes to weight gain. “The ideal weight to gain during pregnancy is different for everyone," doula Ashley Blankenship told Mom.com. "It depends on your weight before getting pregnant, how you’re feeling, and what your diet consists of.”

And while seeing your weight go up isn’t always easy, Blankenship says good nutrition comes first. “Your body and your baby’s body need sustenance. Strict diets have been shown to have adverse effects on babies’ development and birth weights,” she advised. Blankenship recommends a diet of eating whole, nutritious, fresh, and diverse foods, eat when you’re hungry and be mindful of portion control.

This pregnancy calculator will help you monitor your weight gain progress throughout your pregnancy. It takes the basic information of your height, pre-pregnancy weight and what week you are in, and will provide you with a target weight gain amount per week and a target total weight based on the week of the pregnancy. Use this to guide your pregnancy weight gain goals.

“I had so much morning sickness at the start of my pregnancy, I worried that I wasn’t gaining enough weight,” Rita Garcia told Mom.com. “I used the pregnancy calculator to track my weight and make sure that I was moving in the right direction early on.”

Excessive weight gain during pregnancy could signal medical problems such as gestational diabetes or preeclampsia. Work with your doctor if you feel that you are not gaining enough weight or gaining too much weight. Your doctor may have a diet plan to suggest for you.

Working hard to maintain the ideal weight helps ensure that your baby will be healthy and that you’ll be able to take the pregnancy weight off easier in your postpartum months.

Blankenship says that the key to maintaining the ideal weight during pregnancy is to eat frequent, small meals. This will prevent you from gorging yourself and becoming more uncomfortable than you already are.

According to MedlinePlus, you should eat:

• 1,800 calories per day in the first trimester
• 2,200 calories per day in the second trimester
• 2,400 calories per day in the third trimester

Look for a balanced diet that is rich in nutrients and be sure to maintain an exercise regimen. Your exercise doesn’t need to be strenuous — going for long walks or prenatal yoga are great exercise programs to start. Remember that most of the weight that you gain during pregnancy isn’t fat, but is part of growing a baby and necessary.

Here’s an average breakdown of what your pregnancy weight consists of:

• Baby: 8 pounds
• Placenta: 2 to 3 pounds
• Amniotic fluid: 2 to 3 pounds
• Breast tissue: 2 to 3 pounds
• Blood supply: 4 pounds
• Fat stores: 5 to 9 pounds
• Uterus growth: 2 to 5 pounds

As you can see, there is a lot that goes into growing your baby. Keep an eye on the big picture and do what you can to eat well and exercise to manage the upcoming weight gain.