AtlasCalc❤️ HealthbeginnerOffline
Pregnancy Due Date
Estimated due date from last menstrual period.
Inputs
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Result
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How it works
The formula behind this calculator.
EDD = LMP + 280 days (Naegele's rule)
- LMP
- First day of last menstrual period
Naegele's rule adds 7 days to the LMP, then 3 months back, then 1 year. It assumes a 28-day cycle and ovulation on day 14.
Example: LMP = 2024-01-15 → EDD ≈ 2024-10-21
Ref: Naegele (1812)
Tips
- 💡 Naegele's rule assumes a 28-day cycle. If your cycle is longer or shorter, the date shifts accordingly.
- 💡 This is an estimate. Always confirm gestational age with your OB via ultrasound.