Pregnancy Week Calculator Based On LMP

Pregnancy Week Formula:

\[ WP = \lfloor \frac{CD - LMP}{7} \rfloor \]

Pregnancy Week (WP):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Pregnancy Week Calculator?

The Pregnancy Week Calculator estimates the current week of pregnancy based on the Last Menstrual Period (LMP). It provides an accurate assessment of gestational age, which is essential for prenatal care and monitoring fetal development.

2. How Does the Calculator Work?

The calculator uses the pregnancy week formula:

\[ WP = \lfloor \frac{CD - LMP}{7} \rfloor \]

Where:

\( WP \) — Pregnancy week (weeks)
\( CD \) — Current date (date)
\( LMP \) — Last menstrual period (date)
\( \lfloor \rfloor \) — Floor function (rounds down to nearest integer)

Explanation: The formula calculates the number of days between current date and LMP, then divides by 7 and rounds down to get the complete weeks of pregnancy.

3. Importance of Pregnancy Week Calculation

Details: Accurate pregnancy week calculation is crucial for tracking fetal development, scheduling prenatal tests, determining due date, and monitoring maternal health throughout pregnancy.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period and the current date. Both dates must be valid and LMP should be before current date for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why use LMP for pregnancy dating?
A: LMP is the standard method for calculating gestational age as it's typically easier to recall than conception date and provides a consistent reference point.

Q2: How accurate is LMP-based calculation?
A: LMP-based calculation is generally accurate for women with regular 28-day cycles. Ultrasound dating may be more precise for women with irregular cycles.

Q3: What if I don't know my exact LMP?
A: If LMP is uncertain, an early pregnancy ultrasound (6-12 weeks) can provide more accurate gestational age estimation.

Q4: Does this account for conception date?
A: No, this calculator uses LMP which is approximately 2 weeks before conception in a typical 28-day cycle.

Q5: When should I consult a healthcare provider?
A: Always confirm pregnancy dating with a healthcare provider who can consider your individual cycle length and perform necessary examinations.