Quick Calculators

Pregnancy Weight Gain Calculator

Enter your pre-pregnancy weight and height to find your recommended healthy weight gain target.

lbs
ft
in
Recommended Total Weight Gain
25 - 35 lbs
In the 2nd & 3rd trimester, aim for 0.8 - 1.0 lbs per week.
Your Pre-Pregnancy BMI: 23.3•Category: Normal Weight
Guidelines Note: These recommendations are based on the Institute of Medicine (IOM) guidelines for pregnancy weight gain. Every pregnancy is unique. Always consult your obstetrician or midwife regarding your personal health and weight goals.

Healthy Weight Gain During Pregnancy

Watching the scale go up can be stressful, but gaining weight during pregnancy is a beautiful, necessary process. However, gaining too little or too much weight can increase the risk of complications like gestational diabetes, preeclampsia, or preterm birth. Our Pregnancy Weight Gain Calculator uses the official guidelines from the Institute of Medicine (IOM) to give you a personalized target.

It All Starts with BMI

Because every woman starts pregnancy at a different size, there is no "one size fits all" weight gain number. Medical guidelines are entirely based on your Pre-Pregnancy Body Mass Index (BMI).

  • Underweight (BMI < 18.5): Recommended gain of 28 - 40 lbs.
  • Normal Weight (BMI 18.5 - 24.9): Recommended gain of 25 - 35 lbs.
  • Overweight (BMI 25.0 - 29.9): Recommended gain of 15 - 25 lbs.
  • Obese (BMI ≥ 30.0): Recommended gain of 11 - 20 lbs.

The Trimester Timeline

Weight gain isn't a straight line. During the first trimester, the baby is tiny. You only need to gain about 1 to 5 pounds total during these first 13 weeks. If morning sickness causes you to lose a little weight, don't panic; it is very common and usually not harmful.

During the second and third trimesters, the baby begins to grow rapidly. Depending on your BMI, you should aim to gain between 0.5 to 1 pound per week during this phase.

What About Twins?

If you are expecting multiples, you need to gain significantly more weight to support both babies. Women with a normal BMI should aim to gain between 37 and 54 pounds during a twin pregnancy.

Frequently Asked Questions

The recommended weight gain depends entirely on your pre-pregnancy BMI. Women with a normal BMI should gain 25 to 35 lbs. Underweight women should gain 28 to 40 lbs, while overweight women should gain 15 to 25 lbs.
No, 'eating for two' is a myth. During the first trimester, you do not need any extra calories. In the second trimester, you only need about 300 to 350 extra calories per day. In the third trimester, you need about 450 extra calories per day.
The weight isn't just fat! An average 30lb weight gain consists of: the baby (7-8 lbs), larger breasts (2 lbs), larger uterus (2 lbs), placenta (1.5 lbs), amniotic fluid (2 lbs), increased blood volume (3-4 lbs), increased fluid volume (3-4 lbs), and fat stores for delivery/breastfeeding (6-8 lbs).