Pregnancy Weight Gain Calculator
Find your recommended total pregnancy weight gain range based on your pre-pregnancy BMI.
About these guidelines
This calculator uses weight gain ranges published by the Institute of Medicine (IOM), which vary based on pre-pregnancy BMI category — women starting at a lower BMI are generally advised to gain more, while those starting at a higher BMI are advised to gain less.
These are population-level guidelines meant as a general reference — individual recommendations can vary based on other health factors, and any pregnancy weight gain plan should ultimately be discussed with a healthcare provider who knows your full medical history.
Weight gain isn't linear
Most guidelines suggest gaining relatively little in the first trimester (often just 1-5 pounds total) with more consistent weekly gain in the second and third trimesters — attempting to gain the total recommended amount evenly across all nine months doesn't reflect typical healthy patterns.
Twin pregnancies have higher recommended ranges across all BMI categories to support the growth of two babies, reflected in the higher ranges shown when twins is selected.
Frequently asked questions
Are these guidelines the same for every pregnancy?
They're general population guidelines based on pre-pregnancy BMI — individual circumstances can shift what's appropriate, so always discuss your specific situation with a healthcare provider.
Is it normal to gain weight unevenly throughout pregnancy?
Yes — most guidelines expect relatively little gain in the first trimester with more consistent gain in the second and third trimesters, rather than even gain across all nine months.