Pregnancy Weight Gain Calculator
Estimate recommended pregnancy weight-gain ranges from pre-pregnancy BMI for a singleton or twin pregnancy and compare current gain.
Enter your values
Change any assumption and calculate again to compare results.
How the recommended range is chosen
Pregnancy weight-gain recommendations depend on pre-pregnancy body mass index. For a singleton pregnancy, CDC guidance lists total gains of 28–40 lb for BMI below 18.5, 25–35 lb for BMI 18.5–24.9, 15–25 lb for BMI 25.0–29.9, and 11–20 lb for BMI 30 or above. Twin-pregnancy ranges are higher.
The calculator converts your measurements, computes pre-pregnancy BMI, identifies the corresponding category and displays the published total gain range. It also shows how much weight has been gained so far. This is general educational guidance, not an individualized prenatal target.
Why current gain is not labelled “good” or “bad”
Weight gain is not perfectly linear, and pregnancy care depends on fetal growth, medical history, nausea, fluid changes, multiple pregnancy and other factors. A single number cannot determine whether an individual pregnancy is progressing normally.
For that reason, the calculator reports the guideline range and current change without diagnosing whether you are under or over target. Your prenatal clinician can interpret the pattern over time.
Use the right starting weight
Use your best estimate of weight immediately before pregnancy. BMI categories are based on that starting point, not on current pregnancy weight.
If you are pregnant with triplets or more, or have a medical condition affecting weight or fluid balance, use clinician guidance instead of this general calculator.
Important information
This calculator is for general education and planning. It is not a diagnosis, medical device or substitute for individualized healthcare advice. Measurements and formula estimates can differ from clinical assessments.
If the result could affect treatment, pregnancy care, medication, driving, military status or another safety-sensitive decision, confirm it with the appropriate qualified professional or official process.
Frequently Asked Questions
What pregnancy weight gain is recommended at a normal BMI?
For one baby and a pre-pregnancy BMI of 18.5–24.9, CDC guidance lists a total gain of 25–35 lb.
Does the calculator diagnose healthy pregnancy progress?
No. It only compares your entered measurements with general published ranges.
Can I use it for twins?
Yes. Choose twins to use the higher twin-pregnancy total gain ranges published by CDC.