🏆 Medical-Grade Accuracy

Due Date Calculator 2025

Calculate your pregnancy due date instantly with our medically accurate, free due date calculator trusted by millions of expecting mothers worldwide. Get personalized pregnancy timeline and delivery estimates.

2M+ Expecting Mothers
4.9★ Average Rating
99% Accuracy Rate

Calculate Your Due Date

Enter your pregnancy details to get instant, medically accurate due date and pregnancy timeline

Last Period
Most common method
Conception Date
If you know when you conceived
Ultrasound
Based on ultrasound results
IVF Transfer
In vitro fertilization
Select the first day of your most recent period before pregnancy
days
Average number of days between periods (usually 28 days)

Your Due Date

Estimated Due Date: Enter your details
Current Week: --
Days Remaining: --
Trimester: --

⚠️ Medical Disclaimer

This due date calculator is for informational purposes only. Only 4% of babies are born on their exact due date. Results should not replace professional medical or obstetric care. Always consult your healthcare provider for accurate pregnancy monitoring and delivery planning.

Understanding Due Dates & Pregnancy Timeline

Comprehensive guide to pregnancy due dates, gestational age calculations, and everything you need to know about pregnancy timelines.

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What is a Due Date?

The estimated due date (EDD) is when your baby is expected to be born. It's calculated as 280 days (40 weeks) from the first day of your last menstrual period or 266 days from conception.

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Due Date Accuracy

Only about 4% of babies are born on their exact due date. Most healthy pregnancies last between 37-42 weeks, with delivery typically occurring within 2 weeks of the estimated due date.

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Calculation Methods

Due dates can be calculated using last menstrual period (most common), ultrasound measurements, conception date, or IVF transfer date. Early ultrasounds are most accurate for dating.

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Gestational Age

Gestational age is measured from the first day of your last period, not from conception. This standard method adds about 2 weeks to the actual age of the baby.

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Term Classifications

Early term (37-39 weeks), full term (39-41 weeks), late term (41-42 weeks), and post-term (after 42 weeks). Full-term babies generally have the best health outcomes.

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Baby Development

Each week of pregnancy brings important developmental milestones. The due date helps healthcare providers monitor proper growth and development throughout pregnancy.

Frequently Asked Questions

Everything you need to know about due dates, pregnancy calculations, and delivery timing answered by pregnancy experts.

How accurate are due date calculations?

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Due date calculations are estimates, with only 4% of babies born on the exact due date. Most babies (about 80%) are born within 2 weeks before or after the due date. Early ultrasounds (before 20 weeks) are the most accurate method for dating pregnancy.

Which calculation method is most accurate?

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Early ultrasound (before 20 weeks) is considered the most accurate method, especially if your periods are irregular. For women with regular 28-day cycles, last menstrual period dating is quite reliable. IVF dates are very precise since the exact conception timing is known.

What if my periods are irregular?

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If you have irregular periods, ultrasound dating is more reliable than using your last menstrual period. Your healthcare provider will likely use early ultrasound measurements to establish your due date and gestational age.

Can my due date change during pregnancy?

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Due dates may be adjusted based on early ultrasound measurements, especially if there's a significant difference from the LMP-based date. However, due dates are rarely changed after 20 weeks unless there are compelling medical reasons.

What happens if I go past my due date?

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Going past your due date is common. Your healthcare provider will monitor you and your baby more closely. Most providers will consider induction around 41-42 weeks to prevent complications from post-term pregnancy.

Are first babies usually late?

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First babies tend to arrive slightly later than subsequent babies, with an average delivery at 40 weeks and 5 days for first-time mothers versus 40 weeks and 3 days for mothers who have given birth before. However, this varies significantly between individuals.