Useful Utilities

Pregnancy Due Date Calculator

Expected due date from the conception date plus a calendar-correct 280 days, with a gestation timeline in weeks and progress at any check date.

Fill in the values and calculate

Conception date*The day the count starts from
Days your start differs from conception (days)If your records start after the conception date, enter that differenceDefault 0
Check progress on this dateLeave blank to use todayDefault

The form sends itself back to this page — results print below, computed on the server.

No results yet: fill the form above and press Calculate.

About Pregnancy Due Date Calculator

The count is 280 days — forty weeks — run as real calendar days from the conception date, so leap days and month lengths are handled by the calendar rather than a 365-day shortcut.

A timeline prints what day each tenth of the gestation falls on, and a check date converts the due date into progress: percent complete, weeks along and days still to go.

Questions about Pregnancy Due Date Calculator

Why does the due date sometimes shift?

280 days is a mean figure; studies quote a small spread either side of it. The date is the centre of that spread, not a guarantee.

Does my start date change the maths?

Only through the offset field: if your records start days later than the conception date, entering that difference re-anchors every date on the page.

Can I check progress for a future visit?

Yes: any check date works, before or after the due date, so you can plan a meal or a call weeks ahead.

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