Pregnancy Due Date Calculator
Calculate Your Due Date and Track Weekly Pregnancy Milestones
Please enter the required details and click Calculate.
📋How to Calculate Your Due Date
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Enter the first day of your last menstrual period (LMP).
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Adjust for your average cycle length if it is not 28 days.
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Click "Calculate" to view your due date and trimester breakdown.
Our calculator estimates your delivery date using the First Day of Your Last Menstrual Period (LMP). By applying Naegele’s Rule-adding seven days to the first day of your LMP and then adding nine months-the tool determines your 40-week (280-day) gestational timeline.
If you know your exact Conception Date or Date of Ovulation, you can select that method for even greater accuracy.
Useful Tips💡
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Confirm your results with a "dating ultrasound" between weeks 8 and 12 for the highest accuracy.
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If you have irregular cycles, the Conception Date method is often more reliable.
Mistakes to Avoid ⚠️
- Counting pregnancy as exactly 9 months; it is actually 40 weeks (roughly 9 months and 1 week).
- Using the date of intercourse as the "Conception Date"-conception can occur up to 5 days after intercourse.
- Not adjusting the calculation for cycles that are significantly shorter or longer than 28 days.
Understanding Your Pregnancy Timeline
Pregnancies are approximately 40 weeks long (gestational age) from the LMP (according to most obstetrical coding) and are typically divided into trimesters (first - weeks 1-12, second - weeks 13-26, third - weeks 27-40). Without is an actual pregnancy confirmed by ultrasound, there are many milestones to pregnancy including audible heartbeat around 6 weeks of pregnancy, and feeling movement of the baby around 16-20 weeks.
Due dates are estimates, most babies are not born on the estimated due date, and only 5% of babies are born on the exact due date. It's a good idea to ask your doctor for expectorant tracking during your pregnancy.
Practical Applications📊
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Track due date for pregnancy planning.
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Use with our BMI Calculator to monitor weight gain.
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Plan prenatal appointments based on weekly milestones.
Questions and Answers
What is a pregnancy calculator?
A pregnancy estimator computes your delivery date based on your last menstrual period (LMP) or conception date. Our free online estimator provides an estimated delivery date and timeframe for your childbearing.
How to calculate due date from LMP?
To estimate your due date from an LMP, simply add 280 days to the first day of your last period. Our estimator will provide you with accurate, quick results.
Why use a conception date estimator?
f you're certain when you conceived, then the Date of conception estimator will help you know your due date more closely. Our online estimator uses the conception date to more accurately estimate your due date.
What is Naegele's rule?
Naegele's rule estimates your due date by adding 280 days to your LMP. Our pregnancy tracking tool uses Naegele's rule to determine a due date for your estimated delivery date.
What formula does the pregnancy calc use?
Our pregnancy estimator uses Naegele's rule: due date = LMP + 280 days. The 280-day or 40-week standard is widely used by obstetricians in the medical community to track pregnancy.
How accurate is the due date calculator?
The due date estimator is an approximation of your due date. Babies will deliver when they are ready, and not necessarily on the approximate date provided, so use the due date as a guide, but lay your trust in the confirmation of medical professionals when tracking your pregnancy.
Can I use the estimator for IVF pregnancies?
For IVF, yes, you will need to adjust the embryo transfer date for how old the embryo was at transfer. Our tool can estimate your due date based on the conception date for any assisted pregnancy.