See the recommended range of weight gain for your pregnancy. Enter your weight and height before pregnancy and whether you are expecting one baby or twins. This is general guidance, not medical advice. Free, private, and runs entirely in your browser.
Your pre-pregnancy body mass index (BMI) places you in one of four weight categories, and each category has a recommended total gain from the Institute of Medicine guidelines. Twin pregnancies have higher ranges.
How much weight should I gain in pregnancy? For one baby the guideline is 28 to 40 lb if underweight, 25 to 35 lb at a normal weight, 15 to 25 lb if overweight and 11 to 20 lb if obese before pregnancy.
How much for twins? For twins the provisional ranges are 37 to 54 lb at a normal weight, 31 to 50 lb if overweight and 25 to 42 lb if obese.
A woman weighs 140 lb and is 65 in tall. Her BMI is 703 × 140 ÷ 65² ≈ 23.3, which is normal weight. The recommended gain for one baby is 25 to 35 lb, so her weight at term would be about 165 to 175 lb, with 0.8 to 1 lb a week after the first trimester.
Is the weight gain different in the first trimester? Yes. Most people gain only about 1 to 4.4 lb in the first trimester, and the weekly gain applies from week 13.
Should I lose weight while pregnant? Weight loss during pregnancy is not recommended unless a provider advises it.
The Institute of Medicine, now the National Academy of Medicine, first issued pregnancy weight gain guidelines in 1990 and revised them in 2009 to link the ranges to the standard body mass index categories. The CDC and professional bodies still use these ranges. Twin ranges are provisional because less data was available.
Use this calculator to understand the typical range for your situation before a prenatal visit. It is not medical advice, and it does not replace your doctor or midwife, who will consider your health, your history and how the pregnancy is going. If you are concerned about your weight gain, talk to your provider.
What if I have a BMI over 40? The guideline treats all obese categories together. Your provider may set a more personal goal.
Where does the weight go? It is made up of the baby, placenta, amniotic fluid, larger breasts and uterus, extra blood and body fluids, and some fat stores.