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Conception Date Calculator

Estimate when you likely conceived.

Details

Results

Estimated conception date -
Likely conception window -
Based on -

Estimates only - not medical advice.

How it works

Conception usually occurs about 266 days before the due date (or ~14 days after the last period started). We give a best estimate plus a ±3-day window.

This is an estimate. Actual conception depends on your individual cycle and ovulation timing.

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Find more pregnancy and fertility calculators on the home page.

Good to know

FAQs

How accurate is it?

It's an estimate; ovulation timing varies by cycle.

Due date or LMP?

Either works - a dated ultrasound is most precise.

Why a window, not one day?

Sperm can fertilize for several days, so conception falls in a range.

Is this medical advice?

No - confirm with your provider.