Track recommended pregnancy weight gain progression using trimester and BMI-specific guidance.
Overview
Pregnancy weight-gain recommendations differ by pre-pregnancy BMI category to balance maternal and fetal health outcomes.
This calculator estimates total and weekly gain targets, especially during second and third trimesters.
Steps
Use weight before conception or very early pregnancy.
Needed to classify pre-pregnancy BMI.
Assign underweight, normal, overweight, or obesity group.
Select current pregnancy week.
Apply recommended total and weekly gain guidance.
Adjust targets for twins, edema, or medical conditions.
Math
Target Gain by week ≈ FirstTrimesterGain + WeeklyRate x (GestationalWeek - 13); weekly rate depends on pre-pregnancy BMI category
Guidelines use smaller first-trimester gains and BMI-specific weekly gain rates in the second and third trimesters.
Worked cases
Gain ≈ 1.5 kg + 0.42 kg/week x (28 - 13) = 7.8 kg
Target cumulative gain around 7.8 kg by week 28
Gain ≈ 1.0 + 0.28 x (32 - 13) = 6.3 kg
Target gain around 6.3 kg by week 32
Guideline total gain range commonly ~11.5 to 16 kg
Use individual plan with obstetric team
Why use this
Questions