Pregnancy Due Date Calculator — Clear Dates and Simple Timeline

This tool gives three things clearly: your estimated due date, how many weeks and days you are today, and simple trimester checkpoints. The LMP approach adds 280 days from the first day of your last period, then adjusts for cycle length if your cycle is not 28 days. The conception approach adds 266 days and also fits IVF egg retrieval dates. These are standard rules of thumb used worldwide, and they provide a helpful starting point. Your clinician may refine the estimate after an early ultrasound, which directly measures embryo size and can be more precise than calendar math.

Think of the result as a best estimate rather than a promise. Cycles vary, ovulation can shift, and babies arrive on their own schedules. Many births happen between 37 and 42 weeks, with the center around 40 weeks. If anything feels worrying—severe pain, heavy bleeding, unusual symptoms at any stage—contact a clinician or local emergency services promptly. For routine questions, bring your dates to your next appointment; it helps your care team plan scans and labs at the right time.

• Only one date field is needed—enter LMP or Conception and leave the other blank.
• For cycles longer than 28 days, LMP due dates shift later by the difference; shorter cycles shift earlier.
• IVF patients can use the retrieval or fertilization date under the Conception option.

The heading on this page—Pregnancy Due Date Calculator — Clear Dates and Simple Timeline—reflects the experience you get below the form. The calculator displays a single estimated due date, today’s gestational age, and a compact list of milestones such as trimester boundaries and common scan windows. The week-by-week timeline is collapsible so the interface stays clean on phones. You can open it to see when each numbered week begins, which is convenient for scheduling visits or noting personal milestones. Because dates are shown using your browser’s local format, the tool is globally understood without region-specific settings.

Gestational weeks follow clinical convention: counting starts about two weeks before conception. That is why the conception method internally subtracts 14 days to align with the clinical week count. This keeps your results consistent with what you see on medical charts and appointment summaries. If you recently stopped hormonal contraception or your cycles are highly irregular, consider the conception option when a reliable date is available, and expect that a provider may still refine timing after a scan.

Practical tips can make tracking easier. Add appointments and milestone weeks to your calendar after you calculate. Keep a simple journal of symptoms, medications, and questions for each visit. If nausea, sleep issues, or back discomfort are affecting daily life, ask about safe strategies. Nutrition, hydration, movement, and rest matter throughout pregnancy; small, steady steps often help more than big changes. If work or travel plans are on the horizon, the Simple Timeline view makes it easier to balance commitments with prenatal care.

Finally, remember that the Pregnancy Due Date Calculator — Clear Dates and Simple Timeline is an educational tool. It does not replace individual medical advice or emergency care. Use the result to frame conversations with your care team, set reminders for important checkpoints, and follow local guidance for screening and vaccinations as recommended.

LMP method: EDD = LMP + 280 days, then adjust by (cycle length − 28). Conception method: EDD = conception + 266 days. Gestational age uses clinical convention (weeks count from about two weeks before conception). The interface shows trimester transitions and common scan windows so you can plan ahead without digging through notes.