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Understand the method before using any result. The details below describe the purpose and assumptions for this tool.
How the due date calculator works
The due date calculator helps you estimate results using the assumptions and values you provide. Review the formula and example before relying on the result.
Formula and assumptions
A conventional estimated due date is 280 days (40 weeks) from the first day of the last menstrual period; individual clinical dating may differ.
Example
Use the date supplied by your clinician for care decisions.
Important information
Results depend on the values, jurisdiction, date and assumptions you enter. Financial products, tax rules and medical recommendations may vary by location and change over time. Verify critical results with reliable sources.