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Pregnancy Due Date Formula:
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The Pregnancy Due Date Calculator estimates the expected delivery date based on the last menstrual period using the standard formula of adding 280 days (40 weeks) to the LMP date.
The calculator uses the standard pregnancy due date formula:
Where:
Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle and ovulation occurring on day 14.
Details: Accurate due date estimation is crucial for prenatal care planning, monitoring fetal development milestones, and determining the optimal timing for various prenatal tests and screenings.
Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most reliable due date estimation.
Q1: How accurate is the 280-day calculation?
A: While 280 days is the standard, only about 5% of women deliver exactly on their due date. Most deliveries occur within two weeks before or after the estimated date.
Q2: What if my menstrual cycle is longer or shorter than 28 days?
A: For women with regular cycles that are not 28 days, the due date may need adjustment. Consult with your healthcare provider for personalized calculation.
Q3: Can ultrasound provide a more accurate due date?
A: Yes, early pregnancy ultrasound (especially first trimester) can provide a more accurate due date estimation than LMP-based calculations alone.
Q4: When should I contact my healthcare provider?
A: Contact your healthcare provider as soon as you suspect pregnancy to begin proper prenatal care and confirm your due date.
Q5: Are there other methods to calculate due date?
A: Yes, other methods include conception date calculation, IVF transfer date calculation, and fundal height measurement, but LMP remains the most common initial method.