Pregnancy Weight Gain Calculator

Healthy weight gain during pregnancy supports fetal growth, placental development, and maternal energy reserves.

Estimated Due Date
Jan 15, 2027
Current Progress
20w 0d
Second Trimester · 50% complete
Days Until Due Date
140 days
~20 weeks remaining
Pregnancy Progress50%
Week 11st Trimester2nd Trimester3rd TrimesterWeek 40
WEEK 20 — BABY DEVELOPMENT
SIZE COMPARISON
🍓 Banana
APPROX. WEIGHT
300 g
HIGHLIGHTS
Halfway point! Baby can swallow and may suck its thumb.

Key Pregnancy Milestones & Appointments

Week 4: Implantation & Positive Test
May 8, 2026
Week 6: Heartbeat Detectable
May 22, 2026
Week 10: First Prenatal Visit
Jun 19, 2026
Week 12: End of 1st Trimester
Jul 3, 2026
Week 16: Prenatal Screening (Quad Test)
Jul 31, 2026
Week 18: Anatomy Scan & First Kicks
Aug 14, 2026
24
Week 24: Age of ViabilityNEXT
Sep 25, 2026
27
Week 27: End of 2nd Trimester
Oct 16, 2026
28
Week 28: Glucose Tolerance Test
Oct 23, 2026
32
Week 32: Growth Ultrasound
Nov 20, 2026
36
Week 36: Group B Strep Test
Dec 18, 2026
37
Week 37: Early Full Term
Dec 25, 2026
40
Week 40: Estimated Due Date
Jan 15, 2027

Recommended Pregnancy Weight Gain

Based on IOM (Institute of Medicine) guidelines. Enter your pre-pregnancy measurements.

Medical Disclaimer: Estimates are calculated using standard clinical formulas (Naegele's rule for LMP, 266 days post-conception, IVF transfer offsets). Always confirm due date with your OB/GYN or midwife.

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Week-by-week guidance and symptom tracking alongside this calculator.
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Affiliate disclosure: links above may earn us a commission — this never affects the calculation results above.
⚕️MEDICAL & YMYL DISCLAIMERReviewed August 2026

Educational Purpose Only: The calculations, formulas, and estimates provided by this pregnancy & obstetrics calculator are intended solely for educational, research, and informational purposes. They do not constitute medical advice, diagnosis, or personalized treatment plans.

Always consult a qualified healthcare professional, physician, or registered dietitian before making changes to your diet, exercise regimen, calorie intake, or pregnancy care plan. Never disregard or delay professional medical advice because of something you read on this website.

SCIENTIFIC FORMULA & METHODOLOGY
Institute of Medicine (IOM 2009) Pregnancy Guidelines
• Underweight (BMI < 18.5): Gain 28 - 40 lbs (12.5 - 18 kg)
• Normal Weight (BMI 18.5 - 24.9): Gain 25 - 35 lbs (11.5 - 16 kg)
• Overweight (BMI 25 - 29.9): Gain 15 - 25 lbs (7 - 11.5 kg)
• Obese (BMI ≥ 30): Gain 11 - 20 lbs (5 - 9 kg)

The 2009 IOM Guidelines provide clinical target ranges tailored to pre-pregnancy Body Mass Index (BMI) to reduce risks of gestational diabetes, preeclampsia, and macrosomia.

Clinical Limitations & Considerations

Weight gain rates vary significantly throughout pregnancy. Women carrying twins or multiples require higher target weight gain ranges managed directly by an OB-GYN.

Scientific References & Literature

  • Institute of Medicine (IOM) & National Research Council (NRC) (2009). "Weight Gain During Pregnancy: Reexamining the Guidelines." National Academies Press.
  • ACOG Committee Opinion No. 548 (2013). "Weight Gain During Pregnancy." Obstetrics & Gynecology, 121(1), 210-212.

Frequently Asked Questions

How much weight should I gain in the first trimester?

In the first trimester, total expected weight gain is typically minimal (approx. 1 to 5 pounds total) due to morning sickness and early fetal size.