Calculate healthy pregnancy weight gain based on your pre-pregnancy BMI. Get personalized weekly recommendations following IOM medical guidelines.
This calculator uses the Institute of Medicine (IOM) 2009 guidelines a estimate healthy weight gain during pregnancy based on your pre-pregnancy BMI. It provides personalized recommendations for total weight gain, weekly gain rates, and trimester-specific guidance. Remember that every pregnancy is unique, and your healthcare provider is the best source for personalized advice.
The recommended weight gain depends on your pre-pregnancy BMI. Underweight women (BMI < 18.5) should gain 28-40 lbs (12.5-18 kg). Normal weight women (BMI 18.5-24.9) should gain 25-35 lbs (11.5-16 kg). Overweight women (BMI 25-29.9) should gain 15-25 lbs (7-11.5 kg). Obese women (BMI >= 30) should gain 11-20 lbs (5-9 kg).
Twin pregnancies require more weight gain. For normal BMI: 37-54 lbs (16.5-24.5 kg). Overweight: 31-50 lbs (14-22.5 kg). Obese: 25-42 lbs (11-19 kg). Note that twin recommendations are not provided for underweight women as they need individualized care.
In the first trimester, most women gain 1-5 lbs (0.5-2 kg) total. During the second and third trimesters, the recommended rate is 0.5-1 lb (0.2-0.5 kg) per week for normal BMI women. Underweight women may gain slightly more, while overweight and obese women may gain slightly less.
These are general guidelines. Some women naturally gain more or less while still having healthy pregnancies. The most important factor is that your healthcare provider monitors your weight and overall health throughout pregnancy. Do not try a diet or restrict calories during pregnancy without medical supervision.