Pregnancy Due Date Calculator

Enter the first day of your last menstrual period:

🤰 Pregnancy Due Date Calculator

Intro

A pregnancy due date is one of the most important milestones for expectant parents. Knowing when your baby is likely to arrive helps you plan your medical care, lifestyle adjustments, and family preparations. Our Pregnancy Due Date Calculator is a simple yet powerful tool that estimates your baby’s expected arrival date using standard medical formulas.

Instead of guessing, this calculator provides a clear timeline based on your last menstrual period (LMP) or conception date. It’s a must-have tool for mothers-to-be who want to track their pregnancy journey week by week and prepare with confidence.

Formula / Working

The Pregnancy Due Date Calculator works using the Naegle’s Rule, a widely used medical formula.

Formula:
Due Date = First day of Last Menstrual Period (LMP) + 280 days (40 weeks)

For example, if your last period started on January 1, adding 280 days gives you an estimated due date of October 8.

Alternatively, if you know your exact conception date, the calculator adds 266 days (38 weeks) to provide an estimate. Since ovulation usually occurs about two weeks after the first day of your period, both methods lead to nearly the same result.

This tool uses these formulas instantly, saving you from manual counting and reducing the chances of error.

Step-by-Step Usage

Using the Pregnancy Due Date Calculator is quick and easy:

Enter the first day of your last menstrual period (LMP).
Alternatively, if known, enter your conception date.
Select your average cycle length if needed (usually 28 days).
Click the Calculate button.
Instantly view your estimated due date along with your current pregnancy week.

This step-by-step method ensures accuracy and helps expectant mothers stay informed throughout their journey.

Examples

Example 1:
Maria’s last period began on March 5. By adding 280 days, her estimated due date is December 10. The calculator also shows that she is currently in her 12th week of pregnancy.
Example 2:
Aisha knows her exact conception date was April 20. By adding 266 days, the calculator estimates her due date as January 11.

These examples show how the tool adapts to different situations, giving reliable and easy-to-understand results.

FAQs

Q1: How accurate is a pregnancy due date calculator?
A: It provides a reliable estimate, but actual delivery can vary by one to two weeks on either side of the due date.

Q2: Can this calculator predict the exact day of birth?
A: No, it gives an estimate. Only about 5% of babies are born exactly on their due date.

Q3: What if my cycle is longer or shorter than 28 days?
A: The calculator adjusts based on your average cycle length for more accuracy.

Q4: Should I rely only on this calculator?
A: It’s a useful guide, but always confirm your due date with a healthcare professional and ultrasound scans.

Q5: Can I use the calculator without knowing my LMP?
A: Yes, if you know your conception date, the calculator can still give an accurate estimate.