Pregnancy Due Date Calculator
Predict your estimated due date (EDD), track your current gestational age, and map out your trimester milestones instantly.
Calculations Overview
The LMP Method (Naegele's Rule)
Because determining the exact day of conception is difficult, medical professionals start the pregnancy clock from the first day of your Last Menstrual Period (LMP). Naegele's rule calculates the due date by adding 280 days (40 weeks) to the LMP, assuming a 28-day cycle.
IVF & Conception Methods
If you know exactly when conception occurred, or if you underwent IVF, the calculation is highly precise:
- • Known Conception: Add 266 days (38 weeks).
- • IVF 3-Day Transfer: Add 263 days.
- • IVF 5-Day Transfer: Add 261 days.
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Frequently Asked Questions
How is my due date calculated?
Most healthcare providers use Naegele's rule, which estimates your due date by adding 280 days (40 weeks) to the first day of your Last Menstrual Period (LMP). This assumes a standard 28-day cycle with ovulation occurring on day 14.
What if my cycle is longer or shorter than 28 days?
If your cycle is not exactly 28 days, the calculator adjusts the due date by adding or subtracting the difference. For example, if you have a 30-day cycle, ovulation likely occurs on day 16, so your due date is pushed back by 2 days.
Can I calculate my due date using my conception date?
Yes. If you know exactly when you conceived (e.g., through IVF or precise ovulation tracking), the calculator will add 266 days (38 weeks) directly to your conception date to find your Estimated Due Date (EDD).
Is my estimated due date exactly when I will give birth?
Not necessarily. Only about 4% to 5% of babies are born precisely on their estimated due date. A normal, full-term pregnancy can result in delivery anywhere between 37 and 42 weeks.
How are the trimesters broken down?
A typical pregnancy is divided into three trimesters: the First Trimester spans from conception to the end of week 13, the Second Trimester covers week 14 through week 27, and the Third Trimester runs from week 28 until birth.