Pregnancy Due Date Calculator
Anticipating a new arrival? Instantly calculate your estimated due date, track your current trimester, and discover weekly milestones to prepare for your baby's birth.
Due Date
Estimate delivery day
Weekly Progress
Track baby's growth
Trimesters
Know your current stage
Conception
Estimate date of conception
What is a Due Date Calculator?
A simple tool that estimates when your baby will be born based on your last menstrual period or conception date, helping you plan for the journey ahead.
Your Pregnancy Timeline
Pregnancy normally lasts about 40 weeks (280 days) from the first day of your last menstrual period (LMP). While only about 4% of babies are born on their exact due date, this calculation gives you a reliable timeframe for your trimesters, prenatal tests, and delivery window.
Calculate Estimated Due Date (EDD)
Uses the Naegele's Rule to project 40 weeks from your LMP.
Track Weekly Development
See roughly how big your baby is and what developmental changes are happening.
Determine Trimester
Instantly know if you are in the 1st, 2nd, or 3rd trimester.
Plan Ahead
Knowing your date helps with scheduling medical appointments and maternity leave.
Adjustable Cycle
Allows you to adjust your menstrual cycle length (from 21 to 35 days) for a more accurate LMP calculation.
Multiple Methods
Calculate based on the first day of your Last Period or your known Conception Date.
Visual Timeline
A visual progress bar shows you exactly how far along you are in your 40-week journey.
Calculate Your Due Date
Enter your details below to instantly see when you can expect your little one.
How to Use the Due Date Calculator
Follow these simple steps to find out when your baby is arriving and how far along you are.
Select Calculation Method
Choose "Last Period" if you know the first day of your last menstrual cycle (most common). Choose "Conception Date" if you know exactly when conception occurred or the date of IVF transfer.
Enter Dates & Cycle Info
Input the relevant date. If you chose the Last Period method, you can also adjust the cycle length (default is 28 days) to make the calculation more precise for your body.
See Your Baby's Timeline
Click "Calculate Date". You will see your Estimated Due Date (EDD), your current week of pregnancy, a trimester progress chart, and a fun fact about your baby's current development.
Understanding the Trimesters
Pregnancy is divided into three stages, each bringing unique changes for both you and your baby.
| Trimester | Week Range | Key Milestones |
|---|---|---|
| First Trimester | Weeks 1 – 12 | Conception, heartbeat begins, organs form. Morning sickness is common. |
| Second Trimester | Weeks 13 – 27 | Gender reveals, baby movement felt, rapid growth. Energy usually returns. |
| Third Trimester | Weeks 28 – 40+ | Lungs mature, baby gains weight, positioning for birth. Preparation for delivery. |
Calculation Logic & Prenatal Tips
Understand how your due date is calculated using medical standards and what to focus on for a healthy pregnancy.
Naegele's Rule
The standard medical formula used to estimate due dates is called Naegele's Rule. It assumes a regular 28-day cycle and conception occurring 14 days after the start of your period.
The Formula:
LMP Date + 280 Days
If your cycle is longer or shorter than 28 days, the calculator adds or subtracts the difference.
Conception Date Calculation
If you know the exact date of ovulation or IVF transfer, the calculation is more direct. Human gestation typically lasts 38 weeks (266 days) from the moment of fertilization.
The Formula:
Conception Date + 266 Days
Essential Prenatal Care
Nutrition & Vitamins
A balanced diet is crucial for fetal development.
- Take Folic Acid daily (prevents neural tube defects).
- Increase Iron and Calcium intake.
- Stay hydrated with plenty of water.
- Avoid raw meats, certain fish, and unpasteurized dairy.
Medical Checkups
Regular prenatal visits ensure everything is progressing smoothly.
- Schedule your first prenatal appointment early.
- Monitor blood pressure and weight gain.
- Discuss screening tests and ultrasounds.
- Consult doctor before taking medications.
Preparing for Baby
Use your estimated due date to timeline important preparations for your new arrival.
Hospital & Doctor Selection
Knowing your date allows you to research hospitals and birthing centers well in advance. It also helps you schedule tours and register for birthing classes which typically fill up quickly.
Nursery & Baby Gear
The second trimester (weeks 13-27) is often the best time to shop and set up the nursery, as energy levels are usually higher. Use your timeline to plan when to order furniture to ensure it arrives before the baby.
Maternity/Paternity Leave
Your due date is essential for notifying your employer and planning maternity or paternity leave. Most companies require notice 30 days in advance of the expected date.
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Frequently Asked Questions
Common questions about pregnancy dating and calculations.
Due date calculators provide an estimate. Only about 4-5% of babies are born on their exact due date. Most babies arrive within two weeks before or after this date. An ultrasound performed by your doctor usually provides the most accurate dating.
Most women do not know the exact date of conception, but they do know when their last period started. Medical professionals use the Last Menstrual Period (LMP) as the standard baseline to date a pregnancy, assuming ovulation occurred around day 14 of the cycle.
The calculator allows you to adjust your cycle length. If your cycle is longer than 28 days, your due date will likely be pushed later. If it is shorter, your due date will be earlier. This adjustment helps make the calculation more accurate for your body.
Yes. Your doctor might change your due date after an early ultrasound measurement of the baby, which is considered more precise than LMP dating, especially if you have irregular periods.
Absolutely. This calculation happens entirely in your browser. We do not record or store your dates or pregnancy information.
Need Medical Advice?
While this tool is helpful for planning, always consult your healthcare provider for official dating scans and medical advice.
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