🤰 Pregnancy Due Date Calculator
How It Works
Estimate a pregnancy due date from the first day of the last menstrual period. Use Pregnancy Due Date Calculator as a general estimate from the measurements and assumptions you enter.
The result is most useful when the inputs match the definitions used by this calculator. For this tool, the underlying method is: Estimated due date = LMP + 280 days. Compare the output with the worked example, then change one meaningful input at a time to see how the result responds.
Understanding Pregnancy Due Date
Pregnancy Due Date is a general health or fitness estimate based on the measurements and assumptions requested by the calculator. Health estimates are not diagnoses and can differ from an individual's actual needs or measurements. Review the pregnancy due date inputs and units before relying on the result.
When to Use This Calculator
Use Pregnancy Due Date Calculator as a general estimate from the measurements and assumptions you enter.
Practical tip: For this Pregnancy Due Date Calculator, use the result as a starting estimate and change one measurement or activity assumption at a time so you can see how sensitive the estimate is.
Formula
Estimated due date = LMP + 280 days
Example
A due date is commonly estimated as 40 weeks from the first day of the last menstrual period.