1. What is the Due Date Calculator?

The Due Date Calculator estimates the expected delivery date based on the date of ovulation. This method is particularly accurate when the ovulation date is known, such as in fertility treatments or when tracking ovulation.

2. How Does the Calculator Work?

The calculator uses the following calculation:

Where:

• 266 days — Average length of human pregnancy from ovulation
• Ovulation Date — The known date when ovulation occurred

Explanation: Pregnancy typically lasts 266 days (38 weeks) from ovulation, or 280 days (40 weeks) from the first day of the last menstrual period (LMP).

3. Importance of Accurate Due Date Calculation

Details: An accurate due date helps monitor fetal development, schedule prenatal tests at appropriate times, and determine if a pregnancy is progressing normally or if intervention might be needed.

4. Using the Calculator

Tips: Enter the known ovulation date. The calculator will add 266 days to estimate the due date. This method is most accurate when the exact ovulation date is known.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: When the ovulation date is known precisely, this method is very accurate. Only about 5% of women deliver on their exact due date, but most deliver within 2 weeks before or after.

Q2: What if I don't know my ovulation date?
A: If you don't know your ovulation date, calculators based on your last menstrual period (LMP) may be used instead, though they're slightly less accurate.

Q3: Why 266 days instead of 280?
A: 280 days (40 weeks) is counted from the first day of the last menstrual period, while 266 days (38 weeks) is from ovulation (typically occurring about 2 weeks after LMP).

Q4: Can the due date change?
A: Early ultrasound measurements may adjust the due date if they differ significantly from the calculated date, especially if done in the first trimester.

Q5: What factors can affect the actual delivery date?
A: Many factors influence delivery timing including maternal health, fetal development, whether it's a first pregnancy, and genetic factors.