IOM & ACOG Clinical Gestational Guidance
Pregnancy Weight Gain Calculator
Monitor and track healthy gestational weight gain week-by-week. Custom targeting models based on pre-pregnancy BMI for singleton and twin pregnancies.
Scenarios:
Physical Profiles
ft
in
lbs
weeks
lbs
Pre-Pregnancy BMI
22.3 (Normal Weight)
Within Recommended Range
Target Gain for Week 20
7.5 lbs β 12.4 lbs
Your Actual Gain
10 lbs
Total Delivery Target
25 lbs β 35 lbs
Min Target (7.5 lbs)Max Target (12.4 lbs)
Gestational Gain Trajectory Curve
Target Range BandYour Current Gain (10 lbs)
Week-by-Week Cumulative Target Ledger
| Gestation Week | Min Cumulative Gain | Max Cumulative Gain |
|---|---|---|
| Week 0 | 0 lbs | 0 lbs |
| Week 2 | 0.2 lbs | 0.7 lbs |
| Week 4 | 0.4 lbs | 1.5 lbs |
| Week 6 | 0.6 lbs | 2.2 lbs |
| Week 8 | 0.7 lbs | 2.9 lbs |
| Week 10 | 0.9 lbs | 3.7 lbs |
| Week 12 | 1.1 lbs | 4.4 lbs |
| Week 14 | 2.7 lbs | 6.4 lbs |
| Week 16 | 4.3 lbs | 8.4 lbs |
| Week 18 | 5.9 lbs | 10.4 lbs |
| Week 20ACTIVE | 7.5 lbs | 12.4 lbs |
| Week 22 | 9.1 lbs | 14.4 lbs |
| Week 24 | 10.7 lbs | 16.4 lbs |
| Week 26 | 12.3 lbs | 18.4 lbs |
| Week 28 | 13.9 lbs | 20.4 lbs |
| Week 30 | 15.5 lbs | 22.4 lbs |
| Week 32 | 17.1 lbs | 24.4 lbs |
| Week 34 | 18.7 lbs | 26.4 lbs |
| Week 36 | 20.3 lbs | 28.4 lbs |
| Week 38 | 21.9 lbs | 30.4 lbs |
| Week 40 | 23.5 lbs | 32.4 lbs |
Frequently Asked Questions
How is pre-pregnancy BMI used to determine pregnancy weight gain targets?βΎ
Medical guidelines from the Institute of Medicine (IOM) utilize your pre-pregnancy Body Mass Index (BMI) to categorize your weight status (underweight, normal weight, overweight, or obese). Since baseline energy stores and metabolic settings differ, each weight status category is assigned a customized total healthy weight gain range and weekly rate target.
Are the weight gain guidelines different for twins or multiples?βΎ
Yes. Carrying twins places significantly higher nutritional, physiological, and volume demands on the maternal body. The recommended weight gain limits are higher across all BMI categories to support the proper growth and development of both babies and reduce early delivery risks.
What should I do if my weight gain is outside the recommended targets?βΎ
The week-by-week curve is an estimation reference tool. Minor fluctuations are completely normal. If your actual gain is consistently below or above the green shaded band, speak with your healthcare provider or dietitian to review nutritional requirements, activity levels, and gestational progress.