Most common method — assumes an average 28-day cycle.
If you know roughly when conception occurred (e.g. from ovulation tracking or IVF).
Your Estimated Due Date
40 weeks from your last period · only ~5% of babies arrive on their exact due date
LMPDue date
Gestational age today—
Current trimester—
Days until due date—
Milestone
Date
How it works
Pick your dating method. Most people use the first day of their last period (LMP); if you know your conception date instead, use that toggle.
Enter the date. That's the only input needed.
We add 280 days. This is the standard "Naegele's rule" estimate — 40 weeks from LMP, or 266 days from conception (accounting for the ~2 weeks before ovulation).
See your progress. Your current gestational age, trimester, and days remaining are calculated from today's date automatically.
Track milestones. Key dates like end of first trimester, viability, and full term are laid out on a timeline, with passed ones marked off.
This is a statistical estimate, not a prediction — only about 5% of babies arrive exactly on their due date. Your OB/midwife's ultrasound-based dating is generally more precise.
This is a general estimate based on standard 40-week (280-day) gestation from LMP or 266 days from conception — actual due dates vary and ultrasound dating may differ. This isn't medical advice; your OB/midwife's dating is the most reliable source.