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Pregnancy Due Date Calculator Calculate estimated due date from last period, conception date, or IVF transfer with progress tracking.

Pregnancy Due Date Calculator illustration
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Pregnancy Due Date Calculator

Calculate estimated due date from last period, conception date, or IVF transfer with progress tracking.

1

Choose Method

Select LMP, conception date, or IVF transfer date.

2

Enter the Date

Input the relevant date for your chosen method.

3

View Results

See estimated due date, gestational age, trimester, and progress bar.

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What Is Pregnancy Due Date Calculator?

The Pregnancy Due Date Calculator estimates your Expected Date of Delivery (EDD) using three different methods: Last Menstrual Period (LMP), conception date, or IVF transfer date. The LMP method (Naegele's rule) adds 280 days (40 weeks) to the first day of your last period and is the most commonly used clinical method. The conception date method adds 266 days, and the IVF transfer method adds 263 days (for a 3-day transfer). The calculator shows your current gestational age in weeks and days, which trimester you are in, a visual progress bar, and key milestone dates including trimester transitions.

Why Use Pregnancy Due Date Calculator?

  • Three calculation methods: LMP, conception, and IVF transfer
  • Shows gestational age, trimester, and visual progress tracking
  • Displays key milestone dates (trimester boundaries)
  • Days remaining countdown to estimated due date

Common Use Cases

Prenatal Care

Track pregnancy progress and plan prenatal appointments.

Birth Planning

Estimate delivery date for maternity leave and preparation.

IVF Patients

Calculate due date from embryo transfer date with adjusted formula.

General Reference

Understand gestational age and trimester milestones.

Technical Guide

The EDD calculation uses Naegele's rule for LMP: EDD = LMP + 280 days. This assumes a 28-day menstrual cycle with ovulation on day 14. For conception date: EDD = conception + 266 days (38 weeks of actual gestation). For IVF 3-day transfer: EDD = transfer + 263 days. Gestational age is calculated from the LMP (or equivalent date), expressed as weeks+days. Trimesters: 1st = weeks 0-12, 2nd = weeks 13-26, 3rd = weeks 27-40. Only about 5% of babies are born on their exact due date; the normal range is 37-42 weeks (term). Factors affecting actual delivery include first vs subsequent pregnancy, maternal age, and multiple gestation.

Tips & Best Practices

  • 1
    Only about 5% of babies are born on their exact due date
  • 2
    Full term is 37-42 weeks โ€” babies born in this range are considered on time
  • 3
    First-time mothers tend to deliver slightly later than the due date
  • 4
    An ultrasound in the first trimester is the most accurate way to determine due date

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Frequently Asked Questions

Q How accurate is the due date calculation?
Only about 5% of babies arrive on the exact due date. Most are born within 2 weeks before or after. First-trimester ultrasound is more accurate than LMP-based calculation.
Q What if my cycle is not 28 days?
The LMP method assumes a 28-day cycle. If your cycle is longer or shorter, the conception date method may be more accurate.
Q When does each trimester start?
First trimester: weeks 1-12. Second trimester: weeks 13-26. Third trimester: weeks 27-40.
Q What is gestational age vs fetal age?
Gestational age is counted from the LMP (about 2 weeks before conception). Fetal age is counted from conception and is approximately 2 weeks less than gestational age.
Q Can exercise change my due date?
No, exercise does not change the due date. However, staying active during pregnancy is generally recommended and may help with labor preparation.

About This Tool

Pregnancy Due Date Calculator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser โ€” your data never leaves your device. No registration or installation required.