Pregnancy Due Date Calculator
Expecting a little one? Our Pregnancy Calculator helps you estimate your baby's due date, see your current gestational age, and count down the days until arrival! Choose your calculation method: Last Menstrual Period (LMP) or Date of Conception.
How to Use the Pregnancy Calculator
- Choose Calculation Method: Select whether you want to calculate based on your "Last Menstrual Period (LMP)" or your "Date of Conception."
- LMP Method: Enter the first day of your last menstrual period and your average menstrual cycle length (typically 28 days, but adjust if you know yours is different).
- Conception Date Method: If you know the approximate date of conception, select this method and enter that date.
- Click "Calculate": Press the "Calculate Due Date & Progress" button.
- View Your Results: The calculator will display:
- Your Estimated Due Date (and the day of the week it falls on).
- Your current Gestational Age (how many weeks and days pregnant you are).
- A live Countdown Timer to your estimated due date.
Understanding Pregnancy Calculations
Pregnancy calculations provide valuable estimates for expectant parents and healthcare providers. Here's a brief overview:
- Last Menstrual Period (LMP) Method: This is the most common method used by healthcare providers to estimate the due date. It assumes a typical 28-day menstrual cycle with ovulation occurring around day 14. The due date is generally calculated as 280 days (or 40 weeks) from the first day of the LMP. Our calculator allows adjustments for different cycle lengths.
- Conception Date Method: If the exact date of conception is known (e.g., through assisted reproductive technologies or ovulation tracking), the due date can be estimated by adding 266 days (or 38 weeks) to the conception date. This is because a full-term pregnancy is typically 38 weeks from conception.
- Gestational Age: This is the age of the pregnancy, measured in weeks and days from the first day of the LMP. It's a standard way to track fetal development and pregnancy milestones.
- Due Date: This is an *estimated* date of delivery. It's important to remember that only a small percentage of babies are born on their exact due date. A normal full-term pregnancy can last anywhere from 38 to 42 weeks.
Ultrasound scans, especially those performed in the first trimester, can provide a more accurate estimation of the due date by measuring the baby's size.
Frequently Asked Questions (FAQ)
What if I have irregular periods? How does that affect the LMP calculation?
If your menstrual cycles are consistently longer or shorter than the average 28 days, inputting your actual average cycle length into the calculator will help adjust the due date estimation for better accuracy with the LMP method. However, for very irregular cycles, an early ultrasound is often the most reliable way to date the pregnancy.
Is one calculation method (LMP vs. Conception Date) more accurate than the other?
If the exact date of conception is known with certainty, using the Conception Date method can be very accurate (adding 266 days). However, many women are unsure of the exact conception date. The LMP method is widely used and generally reliable if periods are regular. An early ultrasound often provides the most accurate dating.
Why does the countdown timer sometimes show a slightly different number of days than just subtracting dates?
The countdown timer calculates the precise time remaining down to the second, based on the current moment and midnight at the start of your due date. Simple date subtraction might just count full calendar days. The live timer gives a more dynamic "time until" feel.
Is my personal information (LMP, conception date) stored by this tool?
No, all calculations are performed client-side within your browser. The dates and cycle length you enter are not sent to our servers or stored by us. Please see our Privacy Policy for more details.