Due Date from Conception Date
EDD when you know the conception or ovulation date — the 266-day embryonic clock.
Medicine dates pregnancy from the LMP, two weeks before conception — so a pregnancy is '4 weeks' when the embryo is 2. This tool handles the bookkeeping: your due date comes from the 266-day embryonic clock, while the announced 'weeks' follow the LMP convention everyone's chart uses.
Formula
For general information only. Pregnancy and infant care decisions must be guided by your treating clinician or midwife — always defer to their assessment.
EDD when you know the conception or ovulation date — the 266-day embryonic clock. The Due Date from Conception Date is a free, private due date from conception tool — every result computes instantly in your browser with no sign-up and no data upload.
About Due Date from Conception Date
Medicine dates pregnancy from the LMP, two weeks before conception — so a pregnancy is '4 weeks' when the embryo is 2. It applies EDD = conception + 266 days; gestational age still counts from LMP-equivalent. Use the Due Date from Conception Date to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Due Date from Conception Date
- 1Enter your details in the Due Date from Conception Date input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Due Date from Conception Date?
- ✓Instant due date from conception result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (ACOG Committee Opinion 700)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Due Date from Conception Date work?+
Medicine dates pregnancy from the LMP, two weeks before conception — so a pregnancy is '4 weeks' when the embryo is 2. The calculation uses the formula: EDD = conception + 266 days; gestational age still counts from LMP-equivalent. Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Due Date from Conception Date accurate, and what is it based on?+
The method is traceable to authoritative sources: ACOG Committee Opinion 700. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Due Date from Conception Date free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is informational only. Always defer to your treating clinician or midwife for pregnancy and infant care decisions.
What can I use the Due Date from Conception Date for?+
It's commonly used for due date from conception, conception calculator, 266 days. EDD when you know the conception or ovulation date — the 266-day embryonic clock.
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