Estimate your pregnancy due date and timeline.

What this pregnancy due date calculator estimates

This calculator estimates an expected due date, often shortened to EDD. The default method uses the first day of the last menstrual period and adds 280 days, which is the common 40-week pregnancy dating convention. If you enter a conception date, the calculator first maps that date back to an LMP-equivalent date by subtracting 14 days. If you enter an ultrasound date, it subtracts the gestational age measured at the scan, then adds 280 days.

That makes the result consistent across all three input modes. The calculator is not trying to predict the exact day a baby will arrive. It is giving a planning date that helps organize appointments, pregnancy weeks, and common milestones.

Why due dates are estimates

A due date is useful because pregnancy care often refers to weeks and days of gestational age. It is still an estimate. Cycle length, ovulation timing, implantation timing, early measurement differences, and clinical judgment can all move the final date. Many babies arrive before or after the estimated day.

For that reason, the page shows gestational age, trimester, days remaining, and milestone dates instead of treating the due date as the only number that matters. The timeline helps you see where the pregnancy sits relative to common checkpoints such as the end of the first trimester, anatomy scan timing, and full term.

How to choose the input method

Use last menstrual period if you know the first day and cycles are reasonably regular. Use conception date if that is the most reliable event you know. Use ultrasound mode when a scan has already dated the pregnancy and you want the timeline to follow that clinical estimate.

If a clinician has given you an official due date, use that for medical planning. This calculator is best for understanding the arithmetic and checking how different inputs move the timeline.

Reading the milestones

Milestone dates are based on the same LMP-equivalent date as the due date. They are planning markers, not diagnostic checks. Pregnancy care varies by country, risk level, and care provider. If a milestone date seems inconsistent with your care plan, the care plan wins.

Use the result as a clear calendar estimate and bring any uncertainty to a midwife, doctor, or qualified pregnancy care professional.