Pregnancy Due Date Calculator

Calculate your estimated delivery date using proven medical methods. Understanding your due date helps you prepare for your baby's arrival and track important milestones.

Calculate Your Due Date

For an interactive due date calculator with personalized results, use our main pregnancy tracker:

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Due Date Calculation Methods

Last Menstrual Period (LMP)

85% accuracy

Most common method used by healthcare providers

Formula: LMP + 280 days (40 weeks)

Based on 28-day cycle average
Assumes ovulation on day 14
Standard medical practice
May need adjustment for irregular cycles

Ultrasound Dating

95% accuracy in first trimester

Medical imaging provides precise measurements

Formula: Based on fetal measurements

Most accurate in early pregnancy
Measures crown-rump length
Accounts for individual development
Preferred when LMP is uncertain

Conception Date

90% accuracy

If you know when conception occurred

Formula: Conception date + 266 days (38 weeks)

Useful for IVF pregnancies
Known ovulation timing
Fertility tracking data
Shorter than LMP method by 14 days

Key Pregnancy Milestones

12

Week 12: End of first trimester

Lower miscarriage risk

20

Week 20: Anatomy scan

Detailed ultrasound examination

24

Week 24: Viability milestone

Baby could survive with intensive care

28

Week 28: Third trimester begins

Rapid brain development

37

Week 37: Early term

Baby considered full-term

40

Week 40: Due date

Expected delivery date

42

Week 42: Post-term

Medical intervention may be needed

Factors That Affect Your Due Date

First-Time Mothers

Tend to deliver closer to or after their due date

Average: 40 weeks + 5 days

Experienced Mothers

Often deliver a few days before their due date

Average: 40 weeks - 2 days

Multiple Pregnancies

Twins and multiples typically arrive earlier

Average: 35-37 weeks

Cycle Length

Longer cycles may mean later ovulation

Adjust due date accordingly

Important Reminders

Only 5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after the estimated due date.

Due dates are estimates. Your baby will arrive when they're ready, typically between 37-42 weeks of pregnancy.

Consult your healthcare provider for the most accurate due date determination, especially if you have irregular periods or uncertainty about your LMP.

When Do Babies Actually Arrive?

25%

Before 39 weeks

50%

Between 39-41 weeks

25%

After 41 weeks

Start Tracking Your Pregnancy

Get personalized week-by-week updates, track symptoms, and countdown to your due date with our comprehensive pregnancy tracker.

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