Pregnancy Weight Gain Calculator
Pregnancy Weight Gain Reference Calculator. Uses published gestational weight-gain reference ranges from the National Academies/IOM and public health guidelines to provide an educational estimate based on pre-pregnancy BMI.
Pregnancy Weight Gain Calculator
Pregnancy Weight Gain Calculator
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Calculation Results Summary
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Pregnancy Weight Gain Reference
Pregnancy Weight Gain Calculator & Trimester Tracker
Pregnancy Weight Gain Reference Calculator. Uses published gestational weight-gain reference ranges from the National Academies/IOM and public health guidelines to provide an educational estimate based on pre-pregnancy BMI.
IOM Gestational Weight Gain Targets
Normal BMI (18.5-24.9): 11.5 - 16.0 kg total (25 - 35 lbs)
IOM Trimester Target Weight Chart
~0.5 kg / week in 2nd/3rd trimester
~0.4 kg / week in 2nd/3rd trimester
~0.3 kg / week in 2nd/3rd trimester
| Category / Level | Reference Range / Metric | Reference Context |
|---|---|---|
| Underweight (<18.5) | 12.5 – 18.0 kg (28 - 40 lbs) | ~0.5 kg / week in 2nd/3rd trimester |
| Normal BMI (18.5-24.9) | 11.5 – 16.0 kg (25 - 35 lbs) | ~0.4 kg / week in 2nd/3rd trimester |
| Overweight (25.0-29.9) | 7.0 – 11.5 kg (15 - 25 lbs) | ~0.3 kg / week in 2nd/3rd trimester |
Frequently Asked Questions
What is the Pregnancy Weight Gain Calculator?
The Pregnancy Weight Gain Calculator is a reference calculator based on ACOG (American College of Obstetricians and Gynecologists) and IOM (Institute of Medicine) guidance. It provides reference estimates for gestational weight gain based on pre-pregnancy BMI.
How to calculate healthy pregnancy weight gain week by week?
To calculate pregnancy weight gain week by week: Enter your current weight, pre-pregnancy weight, and pregnancy week (1 to 40). For a normal pre-pregnancy BMI (18.5–24.9), reference target gain is 1 to 4.5 lbs in the 1st trimester and ~1 lb per week in the 2nd and 3rd trimesters.
How much total weight should you gain during pregnancy?
According to IOM reference guidelines: Underweight (<18.5 BMI) range is 28–40 lbs (12.5–18 kg); Normal BMI (18.5–24.9) range is 25–35 lbs (11.5–16 kg); Overweight (25–29.9 BMI) range is 15–25 lbs (7–11.5 kg); Obese (≥30 BMI) range is 11–20 lbs (5–9 kg).
What is typical first trimester weight gain?
Most women gain between 0.5 and 2.0 kg (1 to 4.5 lbs) total during the first 12 weeks of pregnancy due to minimal fetal weight growth.
Why does pre-pregnancy BMI affect gestational weight targets?
Pre-pregnancy BMI determines initial energy reserves. Maternal-fetal reference guidelines tailor weight targets based on initial BMI.
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