Pregnancy Weight Gain Calculator
Calculate your recommended pregnancy weight gain by trimester based on pre-pregnancy BMI. Uses IOM/ACOG guidelines.
IOM Weight Gain Guidelines
Normal BMI (18.5-24.9)
11.5 to 16 kg total
Recommended total gain over pregnancy
Weekly rate (2nd/3rd tri)
0.35 to 0.5 kg/week
Steady gain after week 12
The Institute of Medicine (IOM) guidelines, endorsed by ACOG, base recommended weight gain on pre-pregnancy BMI. Underweight women should gain more; overweight and obese women should gain less.
Gain by Pre-Pregnancy BMI
Healthy Pregnancy Tips
- ✓Focus on nutrient density, not eating for two
- ✓Aim for 300 extra kcal/day in 2nd trimester
- ✓Limit caffeine to 200mg/day
- ✓Take folic acid and vitamin D supplements
- ✓Stay active with 150 min moderate exercise/week
Why Pregnancy Weight Gain Matters
Gaining within the recommended range reduces risk of gestational diabetes, pre-eclampsia, caesarean delivery, and macrosomia (large baby). Too little gain increases risk of preterm birth and low birth weight. These guidelines are population-level recommendations and individual needs may vary.
Nutrition During Pregnancy
Calorie needs increase by approximately 300 kcal/day in the 2nd trimester and 450 kcal/day in the 3rd trimester. Protein needs increase to 1.1g/kg/day. Key nutrients include folic acid, iron, calcium, vitamin D, omega-3 fatty acids, and iodine.