Pregnancy Due Date Calculator

Estimate Your Baby's Arrival

Our Pregnancy Due Date Calculator helps you estimate when your baby will arrive. It uses two common methods: Naegele's Rule, based on the first day of your last menstrual period (LMP), or the date of conception.

The Formulas Explained

• Naegele's Rule (LMP Method): This is the most common method. It assumes a 28-day menstrual cycle and that ovulation occurs on day 14. The formula is: Due Date = First Day of LMP + 280 days (40 weeks).
• Conception Date Method: If you know the exact date of conception (e.g., from fertility tracking or IVF), this method can be more accurate. The formula is: Due Date = Date of Conception + 266 days (38 weeks).

How to Use the Calculator

1. Choose Calculation Method: Select either 'Last Menstrual Period' or 'Conception Date'.
2. Select Date: Use the date picker to input the relevant date.
3. Calculate: The tool will provide your estimated due date, your current trimester, and how many weeks pregnant you are.

Real-World Example

A woman's last menstrual period began on January 1, 2024.

• Using the LMP method, the calculator adds 280 days.
• The estimated due date would be October 7, 2024.

Frequently Asked Questions (FAQ)

• How accurate is the due date calculator? The due date is an estimate, not a deadline. Only about 5% of babies are born on their exact due date. It provides a timeframe for when you can expect to give birth.
• What if I have an irregular cycle? If your menstrual cycles are not a typical 28 days, the LMP method may be less accurate. The conception date method or an early ultrasound will provide a more precise due date.
• How is the trimester calculated? Pregnancy is divided into three trimesters:
  • First Trimester: Week 1 - Week 13
  • Second Trimester: Week 14 - Week 27
  • Third Trimester: Week 28 - Birth