Pregnancy Due Date Calculator
Fill in the value and the answer updates as you type.
How the Pregnancy Due Date Calculator works
Naegele's rule: due date = first day of last period + 280 days. Only a doctor can confirm a due date.
Inputs and results
The Pregnancy Due Date Calculator takes 1 input and gives 2 results.
What you enter
- First day of last period — starts at 2026-08-01.
What you get
- Estimated due date
- Weeks pregnant today
Pregnancy Due Date Calculator FAQ
How do I use the Pregnancy Due Date Calculator?
Enter first day of last period in the fields, then read estimated due date and weeks pregnant today in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Pregnancy Due Date Calculator calculate?
Estimated due date from the first day of your last period. It returns estimated due date and weeks pregnant today from the 1 value you provide.
What values does the Pregnancy Due Date Calculator start with?
It opens with first day of last period 2026-08-01 so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Pregnancy Due Date Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Pregnancy Due Date Calculator for medical or health decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm medical or health decisions with a qualified professional. See the Disclaimer for more.