There's no single number that fits everyone, no matter what an old chart taped to the fridge might have told your mother. How much weight you should gain depends a lot on the weight you were carrying before you got pregnant, and doctors sort that into a few BMI categories to come up with your own personal target. The CDC and Mayo Clinic both use the same four categories, and the chart below breaks down what each one means for you.
How Much Should You Gain?
| Starting BMI Category | BMI Range | Total Weight Gain | Weekly Rate, 2nd and 3rd Trimester |
|---|---|---|---|
| Underweight | Below 18.5 | 28 to 40 lbs | 1.0 to 1.3 lbs |
| Normal weight | 18.5 to 24.9 | 25 to 35 lbs | 0.8 to 1.0 lbs |
| Overweight | 25.0 to 29.9 | 15 to 25 lbs | 0.5 to 0.7 lbs |
| Obese | 30.0 and above | 11 to 20 lbs | 0.4 to 0.6 lbs |
These ranges come from the National Academy of Medicine and cover a single baby. Carrying twins changes the math by quite a bit, since you're growing two babies and two placentas at once, so lean on your doctor's specific numbers rather than this chart if that's your situation. Our prenatal appointment timeline walks through when you'll get weighed and measured along the way.
Where All That Weight Actually Goes
Only a small slice of what you gain is actually baby. Here's roughly how the rest breaks down, according to Mayo Clinic.
- Baby. Roughly 7 to 8 pounds.
- Fat and nutrient stores your body builds up. About 6 to 8 pounds.
- Extra blood volume. About 3 to 4 pounds.
- Fluid held in your tissues. About 2 to 3 pounds.
- Amniotic fluid. About 2 pounds.
- Your growing uterus. About 2 pounds.
- Breast tissue. About 1 to 3 pounds.
- Placenta. About 1.5 pounds.
Keep Your Own Numbers Somewhere Handy
A chart on a screen only helps so much. Most people end up tracking their real numbers with pen and paper, whether that's stuck on the fridge or tucked inside a pregnancy binder. Grab either version below and fill it in week by week at each appointment.
Pregnancy Weight & Waist Tracker
Print as many copies as you need to track your weight and waist size, week by week.
Once you know your target, our pregnancy nutrition guide can help you get there without turning every meal into a math problem, and our Weekly Pregnancy Calculator keeps you posted on what's happening with your baby along the way.
A Few Common Questions
What if I'm not gaining fast enough?
Slow gain in the first trimester is normal, especially if morning sickness has you living on crackers some days. If your weight stalls well into the second trimester though, your doctor will likely take a closer look, since steady gain is one of the signs your baby is getting what it needs.
What if I've gained more than the chart says?
An extra pound or two here and there isn't something to panic over. Gaining well above your target range for weeks in a row is worth bringing up at your next appointment, since it can raise your risk for things like gestational diabetes and a harder delivery. Your doctor is there to help you adjust course, not to make you feel bad about a number.
Does this apply if I'm having twins?
Not quite. Carrying twins usually means gaining more overall, somewhere around 37 to 54 pounds if you started at a normal weight, with different targets for women who started underweight, overweight or obese. Multiples pregnancies get watched more closely in general, so your doctor's specific numbers matter more than this chart if that's your situation.