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Due date calculator
Estimate your due date from your last period and usual cycle length.
Source-linked preview · Independent clinical and translation review pending.
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Your result
Enter your details to see a result and its reference.
THE LITTLE DETAILS
Made for your everyday.
Adds 280 days to the first day of the last period, adjusted by cycle length minus 28. Irregular cycles reduce reliability. Your clinician’s ultrasound-based dating takes priority.
ACOG ↗Sources checked November 8, 2026. Source links do not imply endorsement.
Three small steps
- Choose dates, units and the applicable reference.
- Enter accurate details; read the conditions before calculating.
- Read the result, method and original sources together.
How should I interpret this result?
Adds 280 days to the first day of the last period, adjusted by cycle length minus 28. Irregular cycles reduce reliability. Your clinician’s ultrasound-based dating takes priority.