Weight Gain Calculator
See a healthy weight-gain range for your pregnancy, based on your starting point and how far along you are.
These ranges come from Institute of Medicine guidelines for a single baby and are general information, not medical advice. Healthy gain varies, and your own provider, who knows your history and any twins or triplets, is the best guide for you.
About pregnancy weight gain
How much weight should I gain in pregnancy?
It depends on your weight before pregnancy. Using Institute of Medicine guidelines for a single baby, a healthy total range is about 12.5 to 18 kg (28 to 40 lb) if you were underweight, 11.5 to 16 kg (25 to 35 lb) at a healthy weight, 7 to 11.5 kg (15 to 25 lb) if overweight, and 5 to 9 kg (11 to 20 lb) if obese. Your provider may suggest a different range for you.
How is the recommended range calculated?
The calculator works out your pre-pregnancy body mass index (BMI) from your height and your weight before pregnancy, then applies the recommended gain range for that BMI category. The by-week figure assumes a small gain in the first trimester and a steady weekly rate after that.
What if I am expecting twins?
These ranges are for a single baby. Recommended gain is higher for twins or more, and varies a lot by situation, so your provider is the right person to guide you. This tool is general information, not medical advice.
I have gained more or less than this. Should I worry?
Healthy pregnancies come in many shapes, and weight can fluctuate week to week for all sorts of reasons. These figures are a rough guide, not a target to hit exactly. If you have any concern about your weight or your baby's growth, talk with your provider.
Sources and further reading
These organizations offer trusted, in-depth guidance. Gentle Apps is independent and not affiliated with them.