Pregnancy Weight Gain Calculator

This calculator estimates a healthy range of weight gain during pregnancy, both the recommended total and roughly how much to have gained by your current week, based on your weight before pregnancy and your height. Weight gain in pregnancy is normal, necessary and healthy: it supports the growing baby, the placenta, extra blood and fluid, and the body's preparation for breastfeeding. But the right amount depends a lot on where you started, which is why the widely used Institute of Medicine guidelines base the recommended range on your pre-pregnancy body mass index. Someone who began at a lower weight is advised to gain more, while someone who began at a higher weight is advised to gain less, because both too little and too much gain carry risks for parent and baby. This tool applies those guidelines. You enter your pre-pregnancy weight, your height and how many weeks pregnant you are, and it returns your pre-pregnancy BMI and category, the recommended total weight-gain range for a single pregnancy, and an indicative range for how much you might reasonably have gained by your current week, since most gain happens steadily through the second and third trimesters after a small gain early on. Use it as a general reference to discuss with your midwife or doctor, who track your progress in the context of your whole health. It is important to understand that this is a guide for single pregnancies based on population averages; twins or more, medical conditions, and individual circumstances change the picture entirely. Pregnancy is not a time to diet, and your lead maternity carer is the right person to advise on your specific situation. This is general information, not medical advice.

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Institute of Medicine guidelines for a single pregnancy. Twins, medical conditions and individuals differ. Pregnancy is not for dieting. Not medical advice.