Free Online Tool

Pregnancy Due Date Calculator

Estimate your due date by last period, conception, ultrasound, or IVF transfer. Track weekly baby development and every key milestone.

4 methods 40-week guide Twins & multiples Free & private
Last Menstrual Period
Calculate based on the first day of your last menstrual period (most common method).
Select the first day of your last period
days
Normal range: 21-35 days (default 28)
Conception Date
Calculate based on the date you ovulated or conceived.
Select the date of ovulation or conception
Ultrasound Date
Calculate based on an ultrasound scan date and gestational age.
Select the date of your ultrasound scan
weeks days
Enter the gestational age from your ultrasound report
IVF Transfer Date
Calculate based on your embryo transfer date.
Select the date of your embryo transfer
This calculator provides an estimate only. Please consult your healthcare provider for accurate dating and medical advice.
Enter your details and click Calculate
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Trimester Breakdown

👶

First Trimester (Weeks 1-12)

  • Baby's organs begin forming
  • Morning sickness common
  • Fatigue and mood changes
  • First prenatal visits
💪

Second Trimester (Weeks 13-26)

  • Energy levels improve
  • Baby bump becomes visible
  • Feel baby's first movements
  • Anatomy scan ultrasound
🤱

Third Trimester (Weeks 27-40)

  • Baby grows rapidly
  • Prepare for delivery
  • More frequent checkups
  • Nesting instincts kick in

How to Use the Pregnancy Calculator

1

Choose Your Method

Select LMP, Conception, Ultrasound, or IVF based on what you know.

2

Enter Your Details

Fill in your date, cycle length, and pregnancy type.

3

Explore Results

View your due date, current week, trimester, and key milestones.

💡 Pro Tip: Use Ultrasound if you've had a scan before 12 weeks — it's the most accurate method. For IVF pregnancies, always use the IVF method with your embryo transfer date.

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Frequently Asked Questions

Only ~5% of babies are born on their exact due date. 80% of births occur within 2 weeks before or after the EDD. Early ultrasounds (before 12 weeks) provide the most accurate dating.

Gestational age is measured from the first day of your last period (~40 weeks total). Fetal age is measured from conception (~38 weeks). Gestational age is about 2 weeks ahead of fetal age.

For IVF: Day 3 transfer → add 263 days to transfer date. Day 5 blastocyst → add 261 days to transfer date. This is the most precise method of estimating due date.

Yes. Twins typically deliver around 37 weeks, and triplets+ around 33-34 weeks. The calculator adjusts the due date based on the pregnancy type you select.

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Privacy & security notice

This pregnancy calculator runs entirely in your web browser. No data is ever transmitted, stored, or logged by our servers. All calculations are instant and completely private.