Health
Pregnancy Due Date
Calculate your estimated due date, current trimester, and weeks along. Supports LMP and conception-date methods.
Guide
How to use the Pregnancy Due Date
The Pregnancy Due Date helps you make a quick estimate, compare scenarios, and understand the numbers behind the result. It is designed for fast planning, with enough context to make the answer useful instead of just a number.
- Enter current measurements as accurately as possible, using the unit system that fits you best.
- Compare the result with the displayed ranges or targets to understand the estimate in context.
- Adjust assumptions such as activity level, sex, age, or goal where the calculator supports them.
Method
How this calculator works
It estimates pregnancy timing using standard gestational calendar rules such as a 280-day pregnancy from LMP.
This calculator is useful for estimating due date, trimester, and weeks along.
Because assumptions matter, try a few values that represent optimistic, typical, and conservative cases.
Health calculators are screening and planning tools, not medical advice. They cannot replace a clinician's evaluation.
Example
Worked example
With a last menstrual period starting March 10, the 280-day rule places the estimated due date in mid-December of the same year. On June 10 you would be about 13 weeks along — right at the boundary between the first and second trimester.
FAQ
Common questions
How accurate is a due date?
Only about 4–5% of babies arrive on their exact due date; most are born within two weeks either side. The estimate is a planning anchor for care milestones, not a prediction of the day.
What is the difference between dating from LMP and from conception?
The LMP method adds 280 days (40 weeks) to the first day of the last menstrual period; conception dating adds 266 days. LMP is the clinical standard because the date is usually known, but it assumes a 28-day cycle — ultrasound dating supersedes both when available.
How are the trimesters divided?
First trimester through week 13, second from 14 through 27, third from 28 to birth. The calculator shows the current week and trimester for any given date.
What information do I need for the Pregnancy Due Date?
You usually need last menstrual period, conception date, or due-date method. You can change the inputs and recalculate as many times as needed.
How does the Pregnancy Due Date calculate the result?
It estimates pregnancy timing using standard gestational calendar rules such as a 280-day pregnancy from LMP.
Are the results exact?
Health calculators are screening and planning tools, not medical advice. They cannot replace a clinician's evaluation.
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Sources