Pregnancy Due Date Calculator

Estimate your baby's due date and how far along you are from your last period.

Estimated due date: Thu, July 30, 1970

That date is more than 42 weeks ago.

Estimated due date: Thu, July 30, 1970Check inputs

This is an educational estimate, not medical advice. Your healthcare provider will confirm your due date.

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How it works

Due dates are traditionally estimated as 280 days (40 weeks) after the first day of your last period, adjusted if your cycle is longer or shorter than 28 days. Only about 1 in 20 babies arrive exactly on their due date.

Formula

Due date = Last period + 280 days + (cycle length − 28)

Example

A last period starting January 1 with a 28-day cycle gives a due date of October 8.

Assumptions & limitations

Results are rounded for display.

Frequently asked questions

How accurate is this?

It's an estimate. An early ultrasound gives the most accurate dating, and your provider may adjust your due date.

What if I don't know my last period?

Your healthcare provider can estimate your due date with an ultrasound.