Pregnancy Weight Gain Calculator

Enter your pre-pregnancy weight, height and how far along you are. See your recommended total gain and where you should be this week.

Units
Height
Number of babies

Not sure how far along you are? Use the due date calculator.

Why pregnancy weight gain matters

Gaining within the recommended range supports your baby's growth. Gaining too little is linked to low birth weight and preterm birth, while gaining too much is linked to gestational diabetes, high blood pressure, cesarean birth and difficulty losing weight afterward. The goal is not eating for two, but steady and balanced gain.

Recommendations by pre-pregnancy BMI

  • BMI under 18.5 (underweight): 28 to 40 lb (12.5 to 18 kg) total
  • BMI 18.5 to 24.9 (normal): 25 to 35 lb (11.5 to 16 kg) total
  • BMI 25 to 29.9 (overweight): 15 to 25 lb (7 to 11.5 kg) total
  • BMI 30 and above (obese): 11 to 20 lb (5 to 9 kg) total

For nutrition tips, see the pregnancy nutrition guide.

Frequently asked questions

How much weight should I gain during pregnancy?

Recommended total gain depends on your pre-pregnancy BMI. For a single baby: underweight 28 to 40 lb (12.5 to 18 kg), normal weight 25 to 35 lb (11.5 to 16 kg), overweight 15 to 25 lb (7 to 11.5 kg) and obese 11 to 20 lb (5 to 9 kg). These are the Institute of Medicine 2009 guidelines.

Is it normal to gain little weight in the first trimester?

Yes. Gain in the first 13 weeks is usually small, around 1 to 4.5 lb (0.5 to 2 kg) in total. With nausea, gaining nothing or losing a little is common. Most gain happens in the second and third trimesters.

How much weight should I gain per week?

In the second and third trimesters, about 0.8 to 1 lb (0.35 to 0.5 kg) per week is recommended for someone who started at a normal weight. It is a bit more if you started underweight and less if you started overweight or obese. A sudden gain of more than 2 lb (1 kg) in a week can signal swelling, so let your provider know.

How much weight should I gain with twins?

Twin pregnancies have higher ranges. If you started at a normal weight, 37 to 54 lb (16.8 to 24.5 kg) is recommended. It is 31 to 50 lb (14.1 to 22.7 kg) for overweight and 25 to 42 lb (11.3 to 19.1 kg) for obese starting weights.

Where does pregnancy weight go?

Only part of it is the baby. The rest is the placenta, amniotic fluid, a larger uterus and breasts, extra blood and body fluid, and fat stored for breastfeeding. Gaining within the recommended range supports healthy growth.