Gaining weight during pregnancy is a normal, healthy, and necessary part of support for your growing baby. The extra weight is not just body fat; it represents the weight of the fetus, placenta, amniotic fluid, enlarged uterus, increased blood volume, and fluid retention. Keeping your weight gain within recommended guidelines promotes a safer pregnancy and delivery.
There is no single weight gain goal that fits all expectant mothers. The recommended amount depends on your pre-pregnancy Body Mass Index (BMI).
Women who start pregnancy underweight need to gain more to support fetal nutrition, while women who start pregnancy in the overweight or obese ranges need to gain less to minimize risk of gestational diabetes, high blood pressure (preeclampsia), and delivery complications.
To track your general gestational weeks and trimesters, check out our gestational progress tracker. To identify the likely date of conception, see our pregnancy conception calculator.
The guidelines for total weight gain during a single pregnancy are: - Underweight (BMI < 18.5): 12.5 to 18.0 kg (28 to 40 lbs) - Normal Weight (BMI 18.5 to 24.9): 11.5 to 16.0 kg (25 to 35 lbs) - Overweight (BMI 25.0 to 29.9): 7.0 to 11.5 kg (15 to 25 lbs) - Obese (BMI >= 30.0): 5.0 to 9.0 kg (11 to 20 lbs)
To calculate your pre-pregnancy BMI class directly, visit our Body Mass Index classifier. For checking body fat ratios, see our body fat percentage calculator.
Weight gain is not uniform. During the first trimester (weeks 1 to 13), the fetus is very small, and typical weight gain is minimal, usually between 0.5 and 2.0 kg (1 to 4.5 lbs) total.
Starting in the second trimester, weight gain accelerates. For normal weight mothers, a rate of 0.36 to 0.45 kg (0.8 to 1.0 lb) per week is recommended. Gaining weight too rapidly can cause physical discomfort, while gaining too slowly warrants review with a healthcare provider.
To calculate your estimated due date, check out our due date estimator. For converting height or weight measurements, use our standard measurement conversions tool.
Suppose a woman has a pre-pregnancy height of 165 cm and weight of 60 kg, and is currently in week 24 of pregnancy.
First, calculate her pre-pregnancy BMI: - BMI = 60 / (1.65 × 1.65) ≈ 22.0. - This falls in the Normal Weight category.
Next, calculate the recommended gain up to week 24: - First trimester gain is estimated at 0.5 kg to 2 kg. - From week 13 to week 24 is 11 weeks of active gain. - Weekly gain range: 0.36 to 0.45 kg. - Additional gain: 11 × 0.36 ≈ 4.0 kg (low) and 11 × 0.45 ≈ 5.0 kg (high). - Total target gain by week 24 = 4.5 to 7.0 kg (10 to 15.4 lbs).