Due date Jan 6, 2027
- Possible window
- Apr 10, 2026-Apr 20, 2026
- Estimated LMP
- Apr 1, 2026
- Method
- Due date minus 266 days
Pregnancy Conception Calculator
Use this free pregnancy conception calculator to estimate conception date, possible conception window, and LMP from a due date.
Research-based formula Estimate limits shown Examples included Private history
Formula steps
- Use the estimated due date as the anchor.
- Subtract about 266 days to estimate conception timing.
- Show a wider window because ovulation and fertilization vary.
How to use the pregnancy conception calculator
- Enter the requested measurements, dates, lab values, or workout details.
- Check that the units and formula assumptions match what the tool is asking for.
- Press the calculate button to see the answer, supporting metrics, and formula steps.
- Read the estimate with the health disclaimer in mind, then copy the result if you need it for notes.
Common uses
Estimate conception timing from a due date.
Find a possible conception window.
Back-calculate an estimated LMP.
Understand why conception dates are approximate.
Examples
Estimated conception date
Approximate range
Estimated LMP
Frequently asked questions
Quick answers about formulas, inputs, estimate limits, professional guidance, examples, and private in-browser history.
What can I use the Pregnancy Conception Calculator for?
Use it for quick educational estimates, planning, comparison, and trend checks. Health and fitness results should be interpreted with context, not as a diagnosis.
How does the Pregnancy Conception Calculator calculate the result?
The calculator estimates conception as about 266 days before the due date and shows a wider possible window.
Is this medical advice?
No. This page provides an educational estimate only. Talk with a qualified health professional before making medical, pregnancy, nutrition, medication, or safety decisions.
Are my health inputs private?
Yes. The calculator runs in your browser tab. Recent answers stay only on the page while you use it and are not sent to a server.