The Conception Calculator

Conceived on April Fools' Day? Here's the Due Date

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

If conception happened on April Fools' Day (April 1), the baby would be due around December 23 the following year.

Conception dateApril 1
Estimated due dateDecember 23
Likely due window (37–42 weeks)December 2 – January 6
Last period probably startedMarch 18

Remember that sex and conception aren't always on the same day: sperm can survive for up to five days, so a holiday celebration could lead to conception a few days later.

Check your own dates with the due date calculator.

Due Date Calculator: Estimate your due date from the first day of your last period.

Open the calculator

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