Pregnancy Weight Gain Calculator

How much weight should you gain in pregnancy?

The healthy amount depends on your body mass index (BMI) before pregnancy. Women who start with a lower BMI need to gain more, and those with a higher BMI need to gain less. These ranges come from the Institute of Medicine guidelines, which doctors around the world use.

Weight gain week by week

Most women gain only 0.5 to 2 kg in the first trimester. After that, weight goes up more steadily until birth.

For example, a woman who is 160 cm tall and weighed 55 kg before pregnancy has a BMI of 21.5, in the normal range. By week 20, a healthy gain is about 3.4 to 5.6 kg, so a gain of 4 kg is on track.

Where does the extra weight go?

Only part of the weight is the baby. The rest is the placenta, amniotic fluid, a larger womb and breasts, extra blood and fluid, and fat stores your body builds up for breastfeeding.

Gaining too much or too little

• Gaining too little can raise the chance of a baby born small or early.
• Gaining too much can raise the chance of gestational diabetes, high blood pressure and a difficult birth, and can make it harder to lose weight afterwards.
• Pregnancy is not the time to diet. If your gain is off track, your doctor or a dietitian can help you adjust what you eat.

Tips for healthy weight gain

• You do not need to eat for two. In the second and third trimesters, most women need only about 300 extra calories a day.
• Choose whole grains, dal, vegetables, fruit, milk and other protein-rich foods.
• Cut down on fried food, sweets and sugary drinks.
• Stay active with walking or prenatal yoga, if your doctor agrees.

Frequently asked questions