Pregnancy Due Date Calculator - LMP, Conception, or Ultrasound
Estimate your due date from LMP, conception date, or ultrasound scan (Naegele's rule)
How it works
- 1Pick a method
LMP (last menstrual period), conception date, or ultrasound scan.
- 2Enter the date
For LMP, add your average cycle length if not 28 days. For ultrasound, add the reported weeks + days.
- 3Read your due date
See the estimated due date and your current gestational age in weeks + days.
About Pregnancy Due Date Calculator - LMP, Conception, or Ultrasound
Free pregnancy due date calculator using Naegele's rule (280 days from LMP). Choose from three input methods - last menstrual period (with cycle length adjustment), known conception date, or an ultrasound scan with the reported gestational age. Also shows your current gestation in weeks and days. Runs entirely in your browser. Pregnancy Due Date Calculator - LMP, Conception, or Ultrasound on 712 Tools runs entirely inside your browser using modern JavaScript APIs - no server ever sees your data. That means instant results, complete privacy, and no upload limits.
Whether you need to estimate your due date from lmp, conception date, or ultrasound scan (naegele's rule) for a debugging session, a quick sanity check, or a production incident, this tool is free to use as many times as you need. There are no watermarks, no sign-up, and no ads inside the tool itself.
Frequently asked questions
How accurate is a due date estimate?
Only about 5% of babies are born on their exact due date. Most arrive within two weeks either side.
Which method is most accurate?
An early ultrasound (before 13 weeks) is usually the most accurate. LMP is close if your cycles are regular.
Is this medical advice?
No - this is informational only. Consult your healthcare provider for a clinical estimate and prenatal care.
Is my data uploaded?
No. All calculations run entirely in your browser.
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