Health

Healthy Pregnancy Weight Gain Tracker

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate recommended weight gain by trimester based on your pre-pregnancy BMI. ACOG guidelines.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

In this article

ACOG Weight Gain Guidelines
Where Does the Weight Go?

ACOG Weight Gain Guidelines

The American College of Obstetricians and Gynecologists recommends weight gain based on pre-pregnancy BMI: Underweight (BMI <18.5): 28-40 lbs. Normal weight (18.5-24.9): 25-35 lbs. Overweight (25-29.9): 15-25 lbs. Obese (30+): 11-20 lbs. Twins: 37-54 lbs regardless of BMI. Most weight gain occurs in the 2nd and 3rd trimesters.

Where Does the Weight Go?

At delivery, the average breakdown: Baby 7-8 lbs, placenta 1.5 lbs, amniotic fluid 2 lbs, uterus growth 2 lbs, breast tissue 2 lbs, blood volume increase 4 lbs, body fluids 4 lbs, fat stores 5-9 lbs. Total: 27-32 lbs for a normal-weight woman. Most women lose 10-15 lbs at delivery and another 10-15 lbs over the following 6 months.

⚡ CalcWolf Insight

A landmark study in Obstetrics & Gynecology found that women who gained within ACOG guidelines had significantly better outcomes: 50% lower C-section rate, 60% lower gestational diabetes rate, and lost pregnancy weight 3x faster postpartum compared to women who gained excessively.

Frequently asked questions

Is it dangerous to gain too much weight during pregnancy?▾

Excess weight gain increases risk of gestational diabetes, preeclampsia, C-section delivery, and postpartum weight retention. It also increases the baby risk for macrosomia (large birth weight) and childhood obesity. However, inadequate gain is also risky — associated with preterm birth and low birth weight.

When should I start gaining weight?▾

Most women gain 1-5 lbs in the first trimester. Significant weight gain begins in the second trimester (weeks 13-27) at roughly 1 lb/week for normal-weight women. Some women lose weight in the first trimester due to morning sickness — this is usually not concerning if weight gain resumes in the second trimester.

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Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →