IOM Gestational Weight Gain
IOM gestational weight gain: the recommended total gain and second/third-trimester weekly rate by pre-pregnancy BMI category (computed from weight and height), singleton or twin.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Pre-pregnancy weight
- 200 lb
- Height
- 64 in
Result: Pre-pregnancy BMI 34.3 (obese): recommended total gain 11-20 lb, 0.5 lb/wk in the 2nd-3rd trimester (singleton).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Underweight
- BMI < 18.5: total 28-40 lb singleton.
- Normal / Overweight
- BMI 18.5-24.9: 25-35 lb; BMI 25-29.9: 15-25 lb singleton.
- Obese
- BMI >= 30: 11-20 lb singleton; provisional twin ranges apply.
What you enter
- Pre-pregnancy weight
- Height
- Twin pregnancy
How this is calculated
Institute of Medicine and National Research Council. Weight Gain During Pregnancy: Reexamining the Guidelines. Washington, DC: National Academies Press; 2009; carried in ACOG Committee Opinion 548. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.