Pregnancy Due Date Calculator

Calculate estimated due date from last menstrual period using Naegele rule. Shows gestational age, trimester, and days remaining.

How to Use Pregnancy Due Date Calculator

The Pregnancy Due Date Calculator estimates your due date using Naegele rule (LMP + 280 days). Enter the first day of your last menstrual period and optionally adjust for your average cycle length (default 28 days). The tool calculates your estimated due date, current gestational age in weeks and days, which trimester you are in, days remaining until the due date, and estimated conception date. The cycle length adjustment accounts for longer or shorter cycles. Note: this is an estimate for informational purposes only — always consult your healthcare provider for medical guidance.

Step-by-Step Instructions

  1. Enter the first day of your last menstrual period
  2. Optionally adjust your average cycle length
  3. Click Calculate Due Date
  4. View due date, gestational age, trimester, and countdown

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