Pregnancy Weight Gain Calculator
Pregnancy Weight Gain Calculator uses your pre-pregnancy height and weight to find your BMI category, then shows your recommended total gain and the healthy range for your current week (IOM guidelines).
Last updated: July 2026
A pregnancy weight gain calculator shows your recommended total and weekly weight gain based on your pre-pregnancy BMI, following Institute of Medicine (IOM) guidelines, and where you should be by your current week.
How to use Pregnancy Weight Gain Calculator
- Enter your pre-pregnancy weight and height.
- Enter how many weeks pregnant you are (and your current weight, optional).
- Read your recommended total gain and week-by-week range.
Frequently asked questions
Which guidelines are used?
The 2009 Institute of Medicine (IOM) recommendations: underweight 12.5–18 kg, normal 11.5–16 kg, overweight 7–11.5 kg, obese 5–9 kg for a single baby.
Does it work for twins?
This version estimates for a single pregnancy. Twin pregnancies have higher recommended gain — ask your provider.
Is my data private?
Yes — nothing is stored; all calculations run in your browser.
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