You enter your pre-pregnancy weight, height, and current week of pregnancy. The tool computes your pre-pregnancy BMI, then looks up the Institute of Medicine (IOM) weight gain recommendation for your BMI category. It estimates how much you should have gained by your current week using a simple linear model (total recommended gain × weeks elapsed ÷ 40). It does not account for twin pregnancies or trimester-specific gain patterns.
No. Twin pregnancies have different weight gain recommendations. This calculator is for singleton pregnancies only. Consult your healthcare provider for twin pregnancy guidance.
The IOM guidelines include a category for overweight individuals (BMI 25-29.9) with a recommended gain of 15–25 lbs. There's also an obese category (BMI 30+) with 11–20 lbs recommended. Your category is determined by your pre-pregnancy BMI.
Insufficient weight gain during pregnancy can increase the risk of complications including preterm birth, low birth weight, and reduced fetal growth. Following IOM guidelines helps support healthy outcomes for both mother and baby.
This calculator assumes steady linear gain across all 40 weeks. In reality, weight gain varies by trimester—typically slower in the first trimester and faster in the second and third. Discuss your individual pattern with your provider.
Pregnancy is not the time to diet or restrict calories below recommended amounts. Focus on nutrient-dense foods and follow your healthcare provider's guidance. Never pursue weight loss during pregnancy without medical supervision.
Estimate only. Results reflect your inputs and standard formulas — they are not financial, tax, legal, health, or investment advice. Verify important decisions with a qualified professional.