Pregnancy Due Date Calculator
Find out your estimated due date and see a timeline of your pregnancy milestones. Simply enter the first day of your last menstrual period.
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Your Comprehensive Pregnancy Due Date Guide
Discovering your estimated due date is one of the most exciting first steps in a pregnancy journey. Our advanced calculator is designed to be more than just a date finder; it's your first companion, providing a complete overview of your pregnancy timeline. Whether you're calculating from your last menstrual period (LMP), a known due date, or a specific conception date for IVF, our tool offers the flexibility and accuracy you need. See your current gestational age, key trimester milestones, and even get a sneak peek into your baby's development this week.
Expert Reviewed for Accuracy
This tool and its medical information have been reviewed by Dr. Emily Carter, OB/GYN, to ensure it provides safe and accurate estimations for expectant parents.
How Our Due Date Calculator Works
We provide three scientifically-recognized methods to estimate your pregnancy timeline:
- From Last Menstrual Period (LMP): This is the most common method. We use Naegele's rule, which adds 280 days (40 weeks) to the first day of your LMP. This is the standard used by most healthcare providers for pregnancies with regular 28-day cycles.
- From a Known Due Date: If your doctor has already given you a due date (perhaps from an ultrasound), you can enter it here to work backward and see your estimated date of conception and other timeline details.
- From Conception Date / IVF: For those who know the exact date of conception or had an IVF transfer, this is the most accurate method. The calculator adds 266 days (38 weeks—the actual length of gestation) to your specified date.
Disclaimer: This calculator provides an estimate and should be used for informational and entertainment purposes only. An early ultrasound performed by your healthcare provider is the most accurate way to determine your baby's gestational age and official due date. Always consult with a doctor for medical advice regarding your pregnancy.
Frequently Asked Questions (FAQ)
How is a due date calculated?
The most common method, Naegele's rule, calculates the due date by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle. Our calculator also allows calculation from a known conception date (adding 266 days) for higher accuracy, especially in cases of IVF.
How accurate is a due date from LMP?
A due date from your LMP is an educated estimate. Only about 5% of babies are born on their exact due date. It's most accurate for women with a regular 28-day menstrual cycle. The most precise method for dating a pregnancy is an early ultrasound performed by your doctor.
Can my due date change?
Yes, it's common for a due date to be adjusted, especially after your first-trimester ultrasound. An ultrasound measures the baby's size to determine a more accurate gestational age. Your healthcare provider will give you the official due date.
What if my periods are irregular?
If you have irregular periods, calculating from your LMP can be inaccurate. In this case, using the 'From Conception/IVF' mode (if you know the date) or relying on an early ultrasound from your doctor will provide a much more reliable due date.
What happens if I go past my due date?
It's very common to go past your due date, especially for first-time mothers. Your doctor will monitor you and your baby closely. If you go too far past your due date (usually 1 to 2 weeks), your doctor may discuss inducing labor.
