Due Date Calculator
A common estimate adds 280 days to the first day of the last menstrual period.
This calculator is free to use. Enable JavaScript to enter your values and see a result instantly.
How it works
A common estimate adds 280 days to the first day of the last menstrual period.
Worked example
A period beginning January 1 gives an estimated due date around early October.
Keep in mind
Clinical dating may differ; consult a qualified professional.