Pregnancy Due Date Calculator
Estimate your baby’s due date from the first day of your last period or the conception date, with current week and trimester dates.
Runs on your device
Result
Results appear here as you type.
What it does
The estimate uses Naegele’s rule: 280 days from the first day of the last menstrual period, adjusted for cycle length. Only about 4% of babies arrive on their due date; your midwife or doctor will confirm it with an ultrasound.
How to use it
- Choose last period or conception date.
- Enter the date and your usual cycle length.
- Read the due date and milestones.
Example
A period starting 1 March 2026 gives a due date of 6 December 2026. Select Try an example above to see it.
When it helps
- Planning maternity leave.
- Understanding appointment schedules.
- Sharing news with family.
Questions
Is the due date exact?
No. A normal term birth is anywhere from 37 to 42 weeks.
Is my data stored?
No. It is calculated in your browser and not saved.
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