Due Date Calculator
Calculate your pregnancy due date instantly using the first day of your last period or conception date. Plan your journey with accurate pregnancy week tracking.
Due Date Calculator:
The Due Date Calculator uses the Naegelé’s Rule to estimate when your baby is likely to be born. By entering the first day of your last period or date of conception, it automatically calculates your expected delivery date (EDD), current gestational week, and trimester stage, helping you monitor pregnancy progress.
Work & Installation — Input to Output Summary:
- Naegelé’s Rule:
Due Date = LMP + 280 days - Alternative (if cycle ≠ 28 days):
Due Date=LMP+280 days+(Cycle Length−28)
Test the Conception Calculator with known sample cases: e.g., a regular 28-day cycle with a known ovulation date, to test the ovulation and conception date logic. Check the acceptance of inputs (cycle length 21- 35 days, unknown cycle length, due date input). Add a check on unrealistic values (e.g., cycle length less than 21 or greater than 40 days) and deal with irregular cycles through a disclaimer. Allow a switch of various input methods (LMP + cycle length, or due date). Visualize with a clear window-of-fertility highlighting. Ensure that the numeric date inputs are friendly and mobile-friendly. Add a disclaimer that the results are approximations and not factual, particularly when the menstrual cycles are irregular or when fertility problems are involved. Use pertinent keywords in headings and meta tags by default in order to achieve SEO. Make sure that it loads fast and is mobile-friendly, and the calculator logic takes into consideration sperm viability and ovulation timing. Lastly, adapt to the foreign audience (DD/MM/YYYY vs MM/DD/YYYY) provided that the locales of your audience contain Bangladesh (where it is used) and allow both of them.
| Input Data | Description | Output |
|---|---|---|
| Last Menstrual Period (LMP) | First day of last menstrual period | Expected Due Date |
| Conception Date | Date of fertilization | Due Date + Gestational Age |
| Cycle Length | Menstrual cycle in days | Adjusted Due Date |
| Today’s Date | For progress tracking | Current Week, Trimester, and Fetal Age |
Frequently Asked Questions - Due Date Calculator:
What is a due date calculator?
It estimates your baby’s expected delivery date based on your last menstrual period or conception date.
How is the due date calculated?
By adding 280 days (40 weeks) to the first day of your last menstrual period using Naegele’s Rule.
Can cycle length affect my due date?
Yes, longer or shorter cycles can slightly shift the expected due date.
What is EDD in pregnancy?
EDD stands for Estimated Due Date, the predicted day your baby may be born.
How accurate is the due date calculator?
It’s an estimate; only 4% of babies are born exactly on their due date.
Can I use conception date instead of LMP?
Yes, you can calculate due date by adding 266 days to the conception date.
What trimester am I in?
The calculator also shows your current trimester based on gestational weeks.
How long is pregnancy in weeks?
A full-term pregnancy is typically about 40 weeks or 280 days.
Is the due date the same for all women?
No, it can vary depending on menstrual cycle and ovulation timing.
Is this calculator free to use?
Yes, it’s 100% free and works instantly online without registration.
