🩺
Due Date Calculator
pregnancy · due date · baby · 出産予定日 · 출산예정일
Naegele rule (280 days) · estimate only, not medical advice.
How to use
- 1
Enter the first day of your last period.
- 2
Adjust your average cycle length.
- 3
See the estimated due date and current progress.
FAQ
Is this tool free?
Yes — no sign-up, no installation, completely free to use right away.
What is this tool?
This tool estimates a pregnancy due date from the last menstrual period. It shows the expected delivery date and how far along the pregnancy is. It's a reassuring way to plan ahead and follow the weeks. The dates you enter aren't stored and everything is calculated in your browser.
How is it calculated?
Naegele’s rule: last period plus 280 days, adjusted for cycle length.