Calculator Pregnancy
Pregnancy weight gain calculator
Healthy pregnancy weight gain is a range, and it depends mostly on your weight before pregnancy. Enter your pre-pregnancy height and weight for your recommended range and weekly rate.
Recommended total weight gain
0lb
By the numbers Context
How much weight gain is healthy in pregnancy
There is no single right number — healthy pregnancy weight gain is a range, and the biggest factor is your weight before pregnancy. The U.S. Institute of Medicine sets recommended ranges by pre-pregnancy BMI: roughly 28–40 lb for those who were underweight, 25–35 lb at a healthy weight, 15–25 lb for those who were overweight, and 11–20 lb for those with obesity. This calculator finds your BMI category and the range that goes with it.
Timing matters too. Very little weight gain is expected in the first trimester (often just a few pounds); most occurs steadily through the second and third trimesters, at around half a pound to a pound a week for someone starting at a healthy weight. Gaining much more or much less than recommended can raise risks for you and the baby, so it is worth discussing your own trajectory with your care team rather than aiming for a number alone.
25–35 lb
recommended total gain at a healthy pre-pregnancy weight
IOM
2nd & 3rd
the trimesters when most healthy weight gain happens
IOM
~1–4.5 lb
the small total typically gained in the first trimester
IOM
Sources: U.S. Institute of Medicine / National Academies (2009) gestational weight-gain guidelines.
Frequently asked questions
How much weight should I gain during pregnancy?
It depends on your pre-pregnancy BMI. The usual ranges are about 28–40 lb if you were underweight, 25–35 lb at a healthy weight, 15–25 lb if overweight, and 11–20 lb if you had obesity. This calculator gives your specific range; carrying twins raises it.
What trimester do you gain the most weight?
The second and third trimesters. The first trimester usually brings only a few pounds; steady gain of around half a pound to a pound a week typically follows in the later trimesters.
How many pounds do you gain in early pregnancy?
Usually not much — commonly around 1 to 4.5 lb across the whole first trimester, and some people lose a little due to nausea. Most healthy weight gain comes later.
Is it possible to not gain weight during pregnancy?
Some people gain very little early on, especially with morning sickness, and those who started at a higher weight have lower recommended gains. But losing weight or gaining well below the recommendation should be discussed with your clinician, as adequate gain supports the baby’s growth.
How is pregnancy weight gain calculated?
It is based on your pre-pregnancy BMI (weight and height before pregnancy), which maps to an IOM recommended total-gain range. This calculator computes your BMI category and the corresponding range and weekly rate.