Pregnancy Weight Gain Calculator
See the recommended total pregnancy weight gain and weekly rate for your pre-pregnancy BMI, for single or twin pregnancies (IOM 2009 guidelines).
For general information only — not medical advice. Results are estimates; talk to a doctor or qualified health professional about your own health.
How to use
- 1Enter your height and pre-pregnancy weight.
- 2Choose single or twin pregnancy.
How it's calculated
IOM 2009 (singletons): BMI < 18.5 → 28–40 lb; 18.5–24.9 → 25–35 lb; 25–29.9 → 15–25 lb; ≥ 30 → 11–20 lb. Twins: 37–54, 31–50 and 25–42 lb for normal, overweight and obese BMI.
Frequently asked questions
Is weight gain even through pregnancy?
No. Most gain in the first trimester is small (about 1–4.5 lb); the weekly rates apply to the second and third trimesters.
What if I gain more or less?
Talk to your midwife or doctor — they'll consider your health, your baby's growth and your diet.
Are there guidelines for underweight twin pregnancies?
The IOM didn't set one because of limited data; your provider will advise.