Ovulation-Based Due Date

266 days from conception / ovulation.

Ovulation-Based Due Date by AIPreciseTools Β· Open the full calculator β†—

How it works

Average pregnancy is 280 days from the last menstrual period, or 266 days from conception/ovulation. This calculator adds 266 days to the date you enter.

Frequently asked questions

Is this exact?

No. It is an estimate based on average length. Your provider will adjust with ultrasound.

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