Due date calculator
Calculate your baby’s expected due date based on the first day of your last menstrual period, conception date, or IVF transfer. Additionally, you will receive important pregnancy milestones and a detailed analysis.
How to calculate your due date
With this calculator, you can calculate your baby's expected due date and track important pregnancy milestones. The tool considers various calculation methods and offers a detailed pregnancy overview. Follow these simple steps:
Choose calculation method
Decide between last menstrual period (LMP), conception date, or IVF transfer date. The LMP method is most commonly used in medicine.
Enter reference date
Enter the corresponding date - depending on the chosen method, the first day of your last menstrual period, conception date, or IVF transfer date.
Adjust cycle length (optional)
With the LMP method, you can specify your individual cycle length (21-35 days, default: 28 days) for a more accurate calculation.
Activate detailed information
Choose whether you want to see important pregnancy milestones and trimester information additionally displayed.
Calculate two dates
Click "Calculate due date" to get your personalized pregnancy plan.
Analyze results
The tool shows you the expected delivery date, your current pregnancy week, trimester, and remaining days until birth.
Track milestones
With details activated, you see important dates like the end of the first trimester (12th week), organ screening (20th week), and other milestones.
Use visualization
The graphical pregnancy scale shows your current progress through the three trimesters.
Due Date Calculator โ Precise Calculation for Expectant Parents
The Due date calculator is a professional tool for calculating the expected delivery date based on various methods. With individual adaptation to last menstrual period, conception date, or IVF transfer, this calculator helps with precise planning of your pregnancy.
4 Calculation Methods
LMP, conception date, IVF 3-day or 5-day transfer โ flexible according to your information.
Pregnancy Progress
Detailed display of current gestational week and trimester overview.
Important Milestones
Automatic calculation of important dates such as ultrasound screenings and trimester transitions.
Why is Due Date Calculation Important?
Accurate knowledge of the expected due date is essential for pregnancy care and planning. The Due Date Calculator helps schedule important examinations and provides orientation for the entire pregnancy progression.
The Due Date Calculator offers significant benefits:
- Precise Date Calculation: Based on medical standards such as Naegele's rule
- Flexible Methods: Calculation according to LMP, conception date, or IVF transfer
- Pregnancy Overview: Current gestational week, trimester, and remaining days
- Important Milestones: Automatic calculation of ultrasound and examination dates
- Cycle Adjustment: Consideration of individual cycle lengths with LMP method
- IVF-Compatible: Special calculation for 3-day and 5-day embryo transfer
Use Cases for the Due Date Calculator
๐คฐ Natural Pregnancy
Calculate the due date based on the first day of your last menstrual period. The calculator also considers varying cycle lengths and gives you a precise estimate for all important dates.
๐งช IVF Treatment
Specifically for artificial insemination: Enter the transfer date and embryo day. The calculator computes the date according to IVF standards and shows you the exact pregnancy progression.
๐ Pregnancy Planning
Plan important dates such as ultrasound examinations, organ screening, or the start of maternity leave. The calculator displays all relevant milestones clearly.
Tips for Using the Due Date Calculator
- Choose the Right Method: LMP (Last Menstrual Period) is the most common method. For known conception date or IVF transfer, select the corresponding option for more accurate results.
- Enter Exact Date: The more precise your information, the more accurate the calculation. With LMP method, the first day of bleeding is crucial, not the last day.
- Consider Cycle Length: With LMP method, you can specify your individual cycle length. This improves accuracy, especially for deviations from the 28-day standard.
- Use Milestones: Activate the "Detailed Milestones" option for an overview of important dates such as end of 1st trimester (12th GW) or organ screening (20th GW).
- Plan Doctor Appointments: The calculated date is an estimate. Only about 4% of babies are born exactly on the calculated date. Discuss the date with your doctor.
Frequently Asked Questions (FAQ)
The due date calculation using Naegele's rule has an accuracy of approximately ยฑ2 weeks. Only 4% of babies are born exactly on the estimated due date. 96% of births occur between weeks 37 and 42 of pregnancy, with most occurring between weeks 38 and 40.
Ultrasound dating (especially between weeks 8-12) is considered the most precise method as it reflects the actual embryonic development. The LMP method is reliable for regular 28-day cycles. For IVF pregnancies, the transfer date provides the most accurate baseline since fertilization and implantation are precisely known.
The due date is primarily determined by biological factors and cannot be actively influenced. Factors such as genetics, placental function, hormonal balance, and the baby's natural development play the decisive role. Stress, diet, and physical activity cannot advance or delay the birth.
The last menstrual period (LMP) calculation starts from the first day of your last period and adds 280 days (40 weeks). The conception date calculation begins with the actual fertilization day and adds 266 days (38 weeks). The 14-day difference occurs because ovulation typically happens about 14 days after the period starts.
The notation "12+3" means: You are in the 12th gestational week plus 3 additional days. You are in your third month and have completed 12 full weeks plus 3 days. The next day you advance to "12+4", until you reach "13+0" (beginning of week 13).
For IVF (in vitro fertilization), the calculation is based on the transfer date. For a 3-day blastocyst transfer, 263 days are added; for a 5-day transfer, 261 days. This method is very precise because the embryo's age is exactly known. The calculated date corresponds to the biological developmental stage at the time of transfer.
Both terms refer to the same calculated day: the anticipated date of birth 40 weeks (280 days) after the first day of the last menstrual period. "Due date" is the most common term, while "estimated delivery date" (EDD) is primarily used in medical documentation. Both are estimates with a natural variance of ยฑ2 weeks.
For irregular cycles (e.g., 25 or 35 days instead of 28), the LMP method can be inaccurate since ovulation doesn't necessarily occur 14 days after the period starts. In these cases, an ultrasound examination between weeks 8 and 12 is recommended to accurately determine the due date based on actual embryo size.
The first trimester begins on the first day of your last menstrual period and encompasses gestational weeks 1 through 13+6 (13 weeks + 6 days). The second trimester extends from week 14+0 to 27+6, and the third trimester from week 28+0 until birth. The trimester division helps categorize the baby's developmental phases and typical pregnancy symptoms.
The first prenatal examination should ideally take place between weeks 6 and 8 of pregnancy. At this time, the embryo is visible on ultrasound and cardiac activity can be detected. For high-risk pregnancies, pre-existing conditions, or IVF, an earlier examination may be advisable. Regular checkups every 4 weeks (every 2 weeks from week 32 onward) are documented in the maternity record.