The Conception Calculator

Due on Cinco de Mayo: When Did You Conceive?

Due dates & conception. Updated . Calculated with the standard pregnancy dating method used by ACOG and the NHS.

A baby due on Cinco de Mayo (May 5) was most likely conceived around August 12 of the previous year.

Due dateMay 5
Most likely conception dateAugust 12
Likely conception windowAugust 9 – August 15
Estimated last periodJuly 29

Only a small share of babies arrive on their exact due date, so a holiday due date is a target rather than a promise.

Use the conception date calculator for your exact dates.

Conception Date Calculator: Find the most likely conception date from your due date.

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This article is general information, not medical advice. Talk to a doctor or midwife about your own pregnancy or fertility.