Health
Conception Date Calculator
Estimate conception date from due date or last menstrual period.
Inputs
Conception Date Calculator
Result
Estimated conception date
Tue Sep 29 2026
- Fertile window
- Sat Sep 26 2026 → Wed Sep 30 2026
- Due date
- Tue Jun 22 2027
How it's calculated
From due date: conception = due − 266 days. From LMP: conception = LMP + (cycle − 14) days.
Common questions
How accurate is this?
It's an estimate — actual conception may vary by a few days depending on ovulation timing.
Which mode should I use?
Use due date if you have an ultrasound-based estimate; otherwise use LMP.
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