🤰 Pregnancy Weight Gain Calculator
Estimate a healthy pregnancy weight gain range based on your pre-pregnancy BMI and how far along you are.
How much weight should you gain during pregnancy?
Healthy gestational weight gain depends mainly on your body mass index (BMI) before pregnancy. Widely used guidelines from the U.S. Institute of Medicine recommend a total gain range for the full pregnancy that is lower for people who started at a higher BMI, since they generally have more energy reserves already available.
How this calculator works
The calculator first estimates your pre-pregnancy BMI from your height and weight, then looks up the recommended total gain range for your BMI category: about 12.5-18 kg if underweight, 11.5-16 kg for normal weight, 7-11.5 kg for overweight, and 5-9 kg for obese (ranges are higher for twin pregnancies). It then estimates a reasonable amount to have gained by your current week, assuming a small first-trimester gain followed by a steady weekly pace through the second and third trimesters.
Weight gain naturally varies week to week and person to person, so treat the "suggested gain by current week" figure as a rough guide rather than a strict target.
This tool is for general educational and planning purposes only and does not replace the personalized guidance of an obstetric care provider, who can account for multiples, pre-existing conditions, and individual pregnancy progress.