This conception calculator estimates the likely conception date and last menstrual period (LMP) based on a known due date. It works backwards from the expected 40-week pregnancy timeline.
Use it if you know (or have been given) a due date and are curious about the approximate window of conception. Results are approximate and not suitable for legal or medical decisions.
Enter your information in the fields above, run the calculation, and review the result to understand what it means for your situation.
Look at the output in the context of your overall goals rather than in isolation. Consider how sensitive the result is to changes in your inputs (for example, adjusting the amount, rate, or time) to understand which factors matter most.
This tool is a simplified model and does not capture every nuance of real life. Treat it as a planning aid, not a guarantee. For important financial or health decisions, combine these results with professional advice and more detailed analysis.