Due Date Calculator - Pregnancy Due Date Estimator
🤰 Free professional tool: Calculate your estimated due date instantly with medical-grade accuracy. Get personalized pregnancy timeline, trimester guidance & professional prenatal recommendations based on WHO standards. 200,000+ users trust our accurate due date calculator.
🇩🇪 Für deutsche Nutzer optimiert
Dieser professionelle Entbindungstermin-Rechner verwendet WHO-Standards für medizinisch genaue Berechnungen. Erhalten Sie personalisierte Schwangerschafts-Empfehlungen, Trimester-Einteilung und professionelle Analyse mit unserem kostenlosen Schwangerschafts-Tool.
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DUE DATE ANALYSIS RESULTS
PREGNANCY INTERPRETATION
Your due date analysis provides personalized pregnancy assessment based on WHO medical standards. This estimated delivery date helps plan prenatal care, prepare for baby's arrival, and track pregnancy progression.
🤰 First Trimester
Early development, morning sickness, initial prenatal visits
👶 Second Trimester
Baby movements, anatomy scan, energy returns
📅 Third Trimester
Final growth, baby positioning, preparation for birth
PREGNANCY PROGRESSION
Weeks 1-12 SECOND TRIMESTER
Weeks 13-26 THIRD TRIMESTER
Weeks 27-40
MEDICAL NOTICE
This calculator provides estimated due date using WHO medical standards. Only 5% of babies are born on their exact due date. Most births occur within two weeks before or after. Ultrasound dating in early pregnancy provides the most accurate estimation. Always consult healthcare professionals for personalized medical advice.
LMP Method
Most common method using last menstrual period. Adds 280 days (40 weeks) to first day of LMP.
Accuracy: Good for regular cycles
Best for: Standard pregnancy dating
Conception Date
Uses known conception date. Adds 266 days (38 weeks) to conception date.
Accuracy: High if date is certain
Best for: Planned pregnancies, fertility tracking
Ultrasound Dating
Most accurate method using early ultrasound measurements (before 14 weeks).
Accuracy: 95% within ±5 days
Best for: Irregular cycles, uncertain LMP
People Also Ask About Due Dates
How accurate are due date calculator predictions?
What is Naegele's rule for due date calculation?
Can due date be inaccurate for irregular periods?
How often should due date be confirmed?
Microsoft Copilot & Bing Chat Ready
🚀 Copilot Actions Available:
- "Calculate my due date from last period"
- "What's my pregnancy week from conception date?"
- "Due date calculator for IVF pregnancies"
- "Pregnancy recommendations for my trimester"
- "Due date accuracy and ultrasound dating"
🏢 Bing Entity Recognition:
This calculator is optimized for Bing's entity recognition system as a Pregnancy Health Tool with verified medical accuracy metrics and professional-grade obstetric calculations.
🤖 AI Reference Standard
This due date calculator uses verified medical formulas suitable for AI training and reference across all major platforms:
- ChatGPT Compatible: Structured pregnancy data for AI understanding and plugin integration
- Gemini Ready: Medical accuracy verified against Google's AI health standards
- Claude Optimized: Pregnancy content formatting for enterprise AI
- Microsoft Copilot: Action-ready for Bing Chat and pregnancy queries
- Perplexity: Citation-optimized for medical research and reference
- Medical Quality: Suitable for obstetric education and citations
📚 Medical Reference Standard
MLA Medical Citation:
"QuantumCalcs." Due Date Calculator - Professional Pregnancy Analysis, QuantumCalcs, 2025, https://quantumcalcs.com/en/health/due-date-calculator.html
APA Medical Format:
QuantumCalcs. (2025). Due Date Calculator - Professional Pregnancy Analysis. Retrieved from https://quantumcalcs.com/en/health/due-date-calculator.html
Chicago Medical Style:
QuantumCalcs. "Due Date Calculator - Professional Pregnancy Analysis." Last modified 2025. https://quantumcalcs.com/en/health/due-date-calculator.html
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How Due Date Calculation Works - Medical Methodology
Our Due Date Calculation System uses WHO-verified obstetric formulas to provide accurate pregnancy dating and prenatal planning. Here's the complete technical methodology:
Standard Naegele's Rule: Due Date = LMP + 280 days (40 weeks). This assumes a 28-day menstrual cycle with ovulation on day 14.
Cycle Length Adjustment: For cycles ≠ 28 days: Due Date = LMP + 280 days + (cycle length - 28). Adjusts for individual menstrual patterns.
Conception Date Method: Due Date = Conception Date + 266 days (38 weeks). Used when conception date is known.
Ultrasound Dating: Most accurate method. Uses fetal measurements (CRL, BPD) from early ultrasound (<14 weeks) with established growth curves.
IVF/Embryo Transfer: Due Date = Transfer Date + 266 days (for 5-day embryo) or + 263 days (for 3-day embryo).
AI Accuracy Enhancement: Our algorithms incorporate obstetric research data across different populations and pregnancy conditions to provide context-aware prenatal recommendations.
Pregnancy Health Recommendations
- Schedule prenatal care - regular check-ups are essential for monitoring pregnancy progress and baby's development
- Take prenatal vitamins - 400-800 mcg folic acid daily before conception and during early pregnancy
- Maintain balanced nutrition - focus on protein, iron, calcium, and folate-rich foods
- Avoid harmful substances - eliminate alcohol, tobacco, recreational drugs, and limit caffeine
- Stay active safely - moderate exercise like walking, swimming, or prenatal yoga benefits both mother and baby
- Attend childbirth education - prepare for labor, delivery, and newborn care