Pregnancy Due Date Calculator | Accurate Pregnancy Timeline

Expecting a baby is an exciting journey, and knowing your due date helps you plan better for prenatal care, appointments, and preparation. A Pregnancy Due Date Calculator estimates your baby’s arrival based on your last menstrual period (LMP) or conception date. It provides an accurate timeline to help you track your pregnancy week by week.

Why Knowing Your Due Date Is Important

• Medical Planning: Schedule prenatal checkups, ultrasounds, and tests at the right time.
• Preparation: Prepare for maternity leave, baby essentials, and hospital arrangements.
• Tracking Development: Understand fetal growth milestones each week.
• Peace of Mind: Helps you stay informed and reduce anxiety about the pregnancy timeline.

Formula for Calculating Due Date

The most common method is Naegele’s Rule:

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

• Alternatively, if using the conception date: Due Date = Conception Date + 266 days (38 weeks)
• This calculation assumes a regular 28-day menstrual cycle. Adjustments may be needed for longer or shorter cycles.

How the Pregnancy Due Date Calculator Works

1. Enter the first day of your last menstrual period (LMP) or conception date.
2. The calculator adds 280 days (or 266 days if using conception date) to estimate the due date.
3. The result includes your estimated due date, current pregnancy week, and trimester.
4. It may also provide a timeline with key milestones for each trimester.

Step-by-Step Example 1: Using LMP

Problem: Last menstrual period (LMP) was on March 1, 2025.
Formula: Due Date = LMP + 280 days
Calculation: March 1, 2025 + 280 days = December 6, 2025
Result: Estimated due date is December 6, 2025.

Step-by-Step Example 2: Using Conception Date

Problem: Conception occurred on March 15, 2025.
Formula: Due Date = Conception Date + 266 days
Calculation: March 15, 2025 + 266 days = December 5, 2025
Result: Estimated due date is December 5, 2025.

FAQs – Pregnancy Due Date Calculator

1. How accurate is the due date?
The due date is an estimate; most babies are born within 2 weeks before or after this date.

2. Can irregular cycles affect the calculation?
Yes, adjustments may be needed if your menstrual cycle is shorter or longer than 28 days.

3. Can I use the conception date instead of LMP?
Yes, use conception date + 266 days to estimate the due date.

4. Does this calculator track pregnancy weeks?
Yes, it shows current pregnancy week based on the input date.

5. Can I find out the trimester?
Yes, the calculator identifies which trimester you are in: 1st (weeks 1–12), 2nd (weeks 13–26), 3rd (weeks 27–40).

6. Can multiple pregnancies affect the calculation?
The due date remains the same, but multiple pregnancies may have different fetal growth patterns. Always consult a doctor.

7. Is ultrasound more accurate than the calculator?
Early ultrasounds can provide more precise gestational age, but the calculator is a good starting estimate.

8. Does the calculator account for preterm or late births?
No, it provides an estimated date; actual birth may be earlier or later.

9. Is this calculator safe and private?
Yes, it does not store any personal information.

10. Can I use it on mobile devices?
Yes, the calculator is fully responsive and works on all modern browsers and devices.