Pregnancy Due Date Calculator

Estimate your due date and see how far along you are, with the dates of important scans and milestones.

Runs in your browser. Nothing is uploaded Free, no sign-up Works on mobile
days
Pick a date.

How to use Pregnancy Due Date Calculator

  1. Choose last period, conception or IVF transfer date.
  2. Pick the date.
  3. Adjust your cycle length if it is not 28 days.

Frequently asked questions

How is the due date calculated?

Using Naegele’s rule: the first day of your last period plus 280 days (40 weeks), adjusted for longer or shorter cycles.

How accurate is the due date?

Only about 4% of babies are born on their due date. Most arrive within two weeks either side. An early ultrasound gives the most accurate date.