Example 1: Normal BMI progression
Input
- Pre-BMI: 22
- Week: 28
Calculation
Gain ≈ 1.5 kg + 0.42 kg/week x (28 - 13) = 7.8 kg
Result
Target cumulative gain around 7.8 kg by week 28
Track recommended pregnancy weight gain progression using trimester and BMI-specific guidance.
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.
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.
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.
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