Pregnancy runs close to ten lunar cycles — about 280 days from the last period, however you count the start. Enter what you know, in whatever terms your chart uses, and we'll do the rest.
The classic method (Naegele's rule). If your cycle runs longer or shorter than 28 days, we'll shift the estimate to account for a later or earlier ovulation.
How Does the Pregnancy Due Date Calculator Work?
Our Pregnancy Due Date Calculator uses the widely accepted Naegele’s Rule, which estimates a full-term pregnancy as 40 weeks (280 days) from the first day of your last menstrual period (LMP).
If your menstrual cycle is longer or shorter than the standard 28-day cycle, the calculator adjusts the estimated due date accordingly to provide a more personalized result.
After calculating your pregnancy timeline, you’ll instantly see:
- Estimated Due Date (EDD)
- Current Pregnancy Week and Day
- Current Trimester
- Estimated Conception Date
- Pregnancy Progress
- Days Remaining Until Your Due Date
This information can help you better understand where you are in your pregnancy and prepare for upcoming milestones.
Why Use Our Free Pregnancy Due Date Calculator?
Our calculator is designed to make pregnancy tracking simple, accurate, and convenient for expecting parents.
Quick and Easy to Use
Get your estimated due date in seconds by entering just two details—your last menstrual period and cycle length.
Track Your Pregnancy Week
Knowing your current pregnancy week helps you understand your baby’s development, monitor important milestones, and prepare for prenatal checkups.
Plan Ahead
Your estimated due date helps you organize prenatal appointments, maternity leave, hospital bag packing, baby shopping, and birth planning.
Free and Accessible
The calculator is completely free to use, works on desktop and mobile devices, and doesn’t require registration or downloads.
Understanding Your Results
After using the calculator, you’ll receive several important pregnancy details.
Estimated Due Date (EDD)
This is the estimated day your baby may arrive. However, it’s important to remember that only a small percentage of babies are born on their exact due date. Most healthy pregnancies result in birth between 37 and 42 weeks.
Pregnancy Week
Your pregnancy week tells you how far along you are and helps you follow your baby’s growth and development.
Current Trimester
Pregnancy is divided into three trimesters:
- First Trimester: Weeks 1–13
- Second Trimester: Weeks 14–27
- Third Trimester: Weeks 28–40
Knowing your trimester helps you understand the physical changes you may experience and the prenatal care recommended during each stage.
Estimated Conception Date
The calculator also provides an approximate conception date based on your last menstrual period and cycle length. This is an estimate and may vary depending on when ovulation occurred.
How Accurate Is a Pregnancy Due Date Calculator?
A Pregnancy Due Date Calculator provides a reliable estimate, but it cannot predict the exact day your baby will be born.
The accuracy depends on factors such as:
- Regularity of your menstrual cycle
- Accuracy of your last menstrual period (LMP)
- Ovulation timing
- Conception date (if known)
- Early pregnancy ultrasound
For people with regular menstrual cycles, an LMP-based due date calculator is generally very accurate. If your cycles are irregular or you’re unsure of your LMP, your healthcare provider may use an early ultrasound to determine your baby’s gestational age more precisely.
When Should You See a Healthcare Provider?
While this calculator is a helpful planning tool, it should never replace professional medical advice.
Schedule your first prenatal appointment as soon as your pregnancy is confirmed. During your visit, your healthcare provider may:
- Confirm your pregnancy
- Estimate your due date
- Perform an ultrasound if needed
- Review your medical history
- Recommend prenatal vitamins and routine tests
Regular prenatal care is essential for monitoring both your health and your baby’s development throughout pregnancy.
Frequently Asked Questions
Can this calculator tell me the exact day my baby will be born?
No. The calculator estimates your due date based on the information you provide. Most babies are born within a few weeks before or after their estimated due date.
Can I use this calculator if I have irregular periods?
Yes, but the results may be less accurate. If your menstrual cycles are irregular, your healthcare provider may recommend an early ultrasound to determine your due date more accurately.
Does cycle length affect my due date?
Yes. People with longer or shorter menstrual cycles often ovulate at different times. Including your average cycle length helps provide a more personalized estimated due date.
Is this calculator free?
Absolutely! Our Free Pregnancy Due Date Calculator is available to everyone and can be used as many times as needed without registration.
Start Calculating Your Pregnancy Due Date Today
Knowing your estimated due date is one of the first and most exciting steps of pregnancy. Use our Free Pregnancy Due Date Calculator to estimate your baby’s due date, track your pregnancy week, understand your trimester, and prepare for the incredible journey ahead. While the calculator offers a reliable estimate, remember that every pregnancy is unique. Be sure to attend regular prenatal appointments and follow your healthcare provider’s guidance for the most accurate pregnancy timeline and the best care for you and your baby.