Pregnancy Weight Gain Calculator
Calculate your recommended pregnancy weight gain based on your pre-pregnancy BMI. Get week-by-week weight gain targets using IOM guidelines.
Enter your pre-pregnancy measurements
All calculations happen in your browser. No data is sent to any server.
Frequently Asked Questions
How much weight should I gain during pregnancy?▾
The IOM recommends 25-35 lbs for normal weight (BMI 18.5-24.9), 28-40 lbs for underweight (BMI below 18.5), 15-25 lbs for overweight (BMI 25-29.9), and 11-20 lbs for obese (BMI 30+). This calculator gives you a personalized week-by-week target.
When does most pregnancy weight gain happen?▾
Most weight gain occurs in the second and third trimesters. During the first trimester, you typically gain only 1-4 lbs total. After week 13, the rate increases to about 0.5-1.3 lbs per week depending on your pre-pregnancy BMI.
What are the IOM pregnancy weight gain guidelines?▾
The Institute of Medicine (IOM) guidelines provide evidence-based weight gain ranges based on pre-pregnancy BMI category. These guidelines are used by healthcare providers worldwide to promote healthy pregnancy outcomes.
Is gaining too much or too little weight during pregnancy dangerous?▾
Yes. Gaining too little increases the risk of preterm birth and low birth weight. Gaining too much increases the risk of gestational diabetes, preeclampsia, and cesarean delivery. Following IOM guidelines helps reduce these risks.
Is this pregnancy weight gain calculator free?▾
Yes. This calculator is completely free, runs entirely in your browser, and requires no signup. No personal health data is sent to any server.