Pregnancy Due Date Calculator
🤰 Calculate Your Due Date
What Is a Pregnancy Calculator?
A pregnancy calculator (also called a due date calculator) estimates when your baby is likely to be born and how far along you are, based on your last menstrual period or conception date. It typically shows your estimated due date (EDD), current pregnancy week, and trimester stage.
How This Calculator Works
This calculator supports two methods:
| Method | Formula | Best for |
|---|---|---|
| Last Menstrual Period (LMP) | LMP + 280 days, adjusted for your average cycle length | Most common method, based on a typical 28-day cycle |
| Conception Date | Conception date + 266 days | More precise for tracked ovulation, IUI, or IVF pregnancies |
If your cycle is longer or shorter than 28 days, the calculator adjusts your due date accordingly — a refinement of the standard Naegele's Rule used by many clinicians.
Pregnancy Trimesters Breakdown
| Trimester | Weeks | What's Happening |
|---|---|---|
| First Trimester | Week 1–13 | Early development of baby; hormonal changes begin |
| Second Trimester | Week 14–27 | Baby growth accelerates; visible baby bump |
| Third Trimester | Week 28–40 | Final development stage; preparing for delivery |
Important Pregnancy Terms
- EDD (Estimated Due Date): Expected delivery date
- Gestational Age: Weeks of pregnancy from LMP
- LMP: Last menstrual period
- Trimester: One of the three roughly 13-week stages of pregnancy
💡 Good to Know
Only a small percentage of babies are born on their exact due date — full-term delivery anywhere between weeks 37 and 42 is considered entirely normal.
Accuracy & Important Notes
- Results are estimates, not exact predictions
- Accuracy depends on having a regular menstrual cycle and correct LMP date
- Ovulation timing can vary, especially with irregular cycles
- Early ultrasound scans generally provide more precise dating
When to Consult a Doctor
- If you're unsure about your LMP date
- If your cycles are irregular
- If the calculated results seem inconsistent with other information
- For medical confirmation via ultrasound dating
Tips for Expecting Mothers
- Maintain a balanced, nutrient-rich diet
- Stay well hydrated
- Take prenatal vitamins as advised by your doctor
- Attend regular antenatal check-ups
- Avoid unnecessary stress and overexertion
⚠️ Not medical advice
This calculator provides an estimate only. Always consult your doctor or midwife for accurate pregnancy assessment, dating scans, and personalised prenatal care.
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Frequently Asked Questions
It's a reasonable estimate, but only a small percentage of babies are born on their exact due date. Delivery anywhere from week 37 to 42 is considered full term.
This calculator adjusts your estimated due date based on your entered cycle length, which improves accuracy for those with longer or shorter cycles.
Use LMP if you're unsure of your exact conception date — it's the most common method. Use conception date if you tracked ovulation precisely or conceived via IUI/IVF.
Yes — especially an early first-trimester ultrasound, which is generally considered the most reliable way to date a pregnancy.
If you're unsure, an early ultrasound scan with your doctor can help establish a more accurate estimated due date.
A full-term pregnancy typically lasts about 40 weeks from the last menstrual period, with anywhere from 37 to 42 weeks considered within a normal range.
Naegele's Rule is the standard clinical method of adding 280 days to the first day of your last menstrual period to estimate a due date, assuming a 28-day cycle.
No — this calculator only estimates dates and pregnancy progress. Gender can typically be determined via ultrasound from around week 18–20.
Based on the LMP method, conception is estimated to occur around two weeks after the start of the last period, assuming a typical cycle.
No — this tool is for general informational purposes only. Regular antenatal check-ups with a qualified doctor or midwife remain essential throughout pregnancy.
