Calculate your estimated pregnancy due date. Free due date calculator.
This pregnancy due date tool lets you estimate your expected delivery date from your last menstrual period or conception date. It is designed for speed and accuracy, running entirely in your browser with no data sent to any server. Whether you are a student, professional, or simply need a quick answer, this calculator provides instant results with clear explanations. Enter the first day of your last menstrual period. The calculator adds 280 days (40 weeks) to estimate your due date, following Naegele rule used by obstetricians. Only about 4% of babies arrive on their exact due date; most arrive within two weeks before or after.
Enter the first day of your last menstrual period. The calculator adds 280 days (40 weeks) to estimate your due date, following Naegele rule used by obstetricians. Only about 4% of babies arrive on their exact due date; most arrive within two weeks before or after.
Expectant parents estimate when their baby will arrive. Obstetricians confirm due date calculations during prenatal visits. Employers plan maternity leave timelines. Family members coordinate travel for expected delivery dates. Healthcare providers schedule prenatal testing milestones.
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Yes, this Pregnancy Due Date calculator is completely free with no signup, no account creation, and no usage limits. All calculations run locally in your browser, so your data stays private and results appear instantly.
This calculator uses standard mathematical formulas and internationally recognized conversion factors. Results are displayed with up to six significant digits of precision. For most everyday uses, the results are more than accurate enough.
Yes, the calculator is fully responsive and works on smartphones, tablets, and desktop computers. The interface automatically adjusts to your screen size. Touch inputs and on-screen keyboards work seamlessly.
Once the page has loaded in your browser, the calculator works without an internet connection. All computation happens locally using JavaScript. Bookmark the page for quick access anytime.
This calculator uses standard, well-established formulas that are widely accepted in education, science, and professional practice. The specific formula is explained in the "How it works" section above.