Pregnancy Weight Gain Calculator
Recommended total gain based on pre-pregnancy BMI (Institute of Medicine guidelines, singleton).
Pre-pregnancy BMI
Pre-pregnancy BMI:
These ranges are general guidance for singleton pregnancies. Twins and medical conditions need individualized care.
Why the recommendation depends on starting BMI
The Institute of Medicine's guidelines set lower total weight-gain targets for people who start pregnancy at a higher BMI, and higher targets for those who start underweight — the goal is a healthy total gain that supports fetal development while managing risks associated with either too little or too much gestational weight gain.
Frequently asked questions
Is this the same for twins or multiples? No — these ranges are specifically for singleton pregnancies. Recommended gain for twin or multiple pregnancies is higher and should be guided by an obstetric care provider.
Is gaining above or below the range dangerous? Gaining outside the recommended range is associated with increased risk of certain complications (for both parent and baby), but individual circumstances vary considerably — this is general population guidance, not a personalized medical assessment.
Should weight gain be even throughout pregnancy? No — gain is typically slower in the first trimester and faster in the second and third, so tracking against the total recommended range (rather than expecting a constant weekly rate) is more appropriate.