Pregnancy Weight Gain Calculator
Track recommended weight gain during pregnancy based on pre-pregnancy BMI and gestational week.
Result
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A pregnancy weight gain calculator shows recommended weight gain by trimester based on your pre-pregnancy BMI and current gestational age.
Examples
Normal BMI at 20 weeks
A woman with a pre-pregnancy BMI of 22 at week 20 should have gained approximately 8-14 lbs. Total recommended gain by week 40: 25-35 lbs.
Frequently Asked Questions
Why does pre-pregnancy BMI matter?
Women who start pregnancy underweight need to gain more to support fetal growth, while women who start overweight or obese have higher baseline energy reserves and need less additional gain to have healthy outcomes.
Is it normal to gain weight unevenly?
Yes. Most women gain only 1-4 lbs in the first trimester, then gain more steadily in the second and third trimesters. Some weeks you may gain more than others, which is normal.
Result
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Quick Tips
- •Focus on nutrient quality rather than strictly hitting a weight number each week.
- •Discuss your weight gain goals with your OB-GYN or midwife at each prenatal visit.
- •Always confirm results with your healthcare provider for personalized guidance.