Pregnancy Calculator
Calculate your estimated due date, current pregnancy week, and trimester based on the first day of your last menstrual period or conception date.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Pregnancy Calculator
- Select Calculation Method: Choose between Last Menstrual Period (LMP) or Conception Date from the dropdown.
- Enter Date: Pick the relevant date (LMP or conception) using the date picker. It defaults to today.
- Set Cycle Length: Enter your average menstrual cycle length (20–45 days; default is 28 days).
- Calculate: Click the Calculate button.
- Review Results: You’ll see:
- Due Date – estimated delivery date.
- Current Week – weeks and days of pregnancy.
- Trimester – current stage (First, Second, or Third).
Note: All inputs are in days (no unit conversion needed). The calculator adjusts for cycle length automatically.
Previous Results
| Result | Inputs | Date |
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Frequently Asked Questions
The due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP), adjusted for your average cycle length. If using conception date, we assume ovulation occurred 14 days before conception and calculate LMP accordingly.
A typical menstrual cycle is 28 days, but cycles can range from 20 to 45 days. The calculator adjusts the due date based on your cycle length.
This calculator provides an estimate based on standard medical assumptions. Actual due dates may vary. Always consult your healthcare provider for accurate pregnancy dating.
