The Institute of Medicine (IOM) publishes recommended total pregnancy weight gain ranges based on pre-pregnancy BMI. Enter your pre-pregnancy height and weight, plus how far along you are, to see your recommended range.
Pregnancy Weight Gain Calculator
LiveIOM recommended total weight gain ranges
| Pre-pregnancy BMI | Recommended total gain |
|---|---|
| Underweight (below 18.5) | 28–40 lb |
| Normal weight (18.5–24.9) | 25–35 lb |
| Overweight (25–29.9) | 15–25 lb |
| Obesity (30+) | 11–20 lb |
A pre-pregnancy height of 5'5" and weight of 140 lb gives a BMI of about 23.3 (normal weight). At week 20: total recommended gain is 25–35 lb over the full pregnancy, with a rough estimate of about 10 lb gained so far.
Step-by-step guide
- Enter your pre-pregnancy height and weight to establish your starting BMI category.
- Enter your current week of pregnancy.
- Compare your category's total recommended range against your prenatal care provider's own tracking, which is the more authoritative source for your specific pregnancy.
Common mistakes
Frequently asked questions
What if I'm gaining faster or slower than this range?
These are general population guidelines — your prenatal care provider tracks your individual progress at each visit and is the right source for guidance specific to you and your pregnancy.
Does this apply to twin pregnancies?
No — this reflects guidelines for a single baby. Twin and multiple pregnancies have their own separate recommended ranges; ask your provider for guidance specific to a multiple pregnancy.
Is gaining weight during pregnancy healthy?
Yes — weight gain during pregnancy supports the baby's growth, the placenta, increased blood volume, and other normal changes. These ranges exist to guide a healthy amount, not to discourage gaining weight.
Related calculators
See more in the Health Calculators section, or try the Pregnancy Due Date Calculator and BMI Calculator.