IOM-recommended weight gain based on your pre-pregnancy BMI and gestational week
Input your pre-pregnancy weight in pounds and your height. The calculator uses these to determine your pre-pregnancy BMI category (underweight, normal, overweight, or obese) according to WHO standards.
Enter how many weeks pregnant you currently are (1-42 weeks). The calculator will show the recommended total weight gain for your BMI category and the expected range by your current week.
The tool displays the IOM-recommended total weight gain range, the expected range by your current week, and the recommended weekly rate for the second and third trimesters. Optionally enter your current weight to see how you're tracking.
The Institute of Medicine recommends: Underweight (BMI < 18.5): 28-40 lbs; Normal (BMI 18.5-24.9): 25-35 lbs; Overweight (BMI 25-29.9): 15-25 lbs; Obese (BMI ≥ 30): 11-20 lbs. These guidelines are for singleton pregnancies.
For most women, the first trimester weight gain is modest — typically 1-5 lbs total. The majority of weight gain occurs in the second and third trimesters at a rate of about 0.5-1 lb per week depending on your BMI category.