Pregnancy weight gain calculator
See a broad evidence-based range for one baby, with context—not judgement.
Direct answer: general pregnancy weight-gain ranges depend on prepregnancy BMI. They span 28–40 lb for BMI below 18.5, 25–35 lb for BMI 18.5–24.9, 15–25 lb for BMI 25–29.9, and 11–20 lb for BMI 30 or higher.
Based on a prepregnancy BMI of 22.8 (normal weight). This is a screening category, not a judgement about your body.
Your entered change is within this broad week-based guide. Weight gain is not perfectly linear; your care professional also considers fetal growth, nutrition, fluid shifts and your health.
How to read this range
The calculation uses your prepregnancy BMI to select the National Academies' general range for an adult carrying one baby. The week-based view assumes 0.5–2 kg (1.1–4.4 lb) across the first trimester, then applies the guideline's average weekly range. It is a conversation aid—not a pass/fail score.
The National Academies guideline summary publishes the total and weekly ranges. The CDC pregnancy weight guidance presents the same singleton ranges and notes that goals are based on BMI before pregnancy.
Common questions
How much weight should I gain during pregnancy?
For one baby, general total ranges are 28–40 lb for a prepregnancy BMI below 18.5, 25–35 lb for BMI 18.5–24.9, 15–25 lb for BMI 25–29.9, and 11–20 lb for BMI 30 or higher. Individual goals need clinical judgement.
Is pregnancy weight gain the same every week?
No. The National Academies guidance assumes a broad first-trimester gain of 0.5–2 kg (1.1–4.4 lb), followed by BMI-specific average weekly ranges. Real weight change is not perfectly linear.
Does this calculator work for twins?
No. This result is for a singleton pregnancy. Recommended ranges differ for twins, and evidence is limited for higher-order pregnancies, so discuss a personal goal with your care team.
Should I diet if the result says I am above the range?
Do not start weight loss or restrictive dieting during pregnancy based on a calculator. Bring your trend and concerns to a qualified maternity-care professional or registered dietitian.
Use the pregnancy water intake calculator for a simple hydration guide, or return to all free tools.