bumpcalc.comConception Date Calculator
Use your due date to estimate your likely conception date and a realistic conception window.
Enter a due date to estimate conception timing.
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Frequently Asked Questions
How do I find out when I conceived?
Enter your estimated due date in the calculator above. It works backward from the due date by subtracting 266 days (38 weeks) to estimate conception. Keep in mind this is an estimate — the actual conception could have occurred within a window of several days around this date.
Can I know the exact date of conception?
It's very difficult to know the exact date. Sperm can survive inside the body for up to 5 days, so conception could have occurred on any day within your fertile window. The calculator provides an estimated date, not a precise one.
How far back from my due date was conception?
Conception typically occurs about 266 days (38 weeks) before the due date, or approximately 2 weeks after the start of your last menstrual period. This is because the standard 40-week pregnancy count includes about 2 weeks before ovulation and conception.