Etg Calculator
Calculate the estimated time of gestation (ETG) based on last menstrual period (LMP) or conception date. Useful for pregnancy due date estimation.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the ETG Calculator
This calculator estimates your due date and current gestational age based on either your last menstrual period (LMP) or conception date.
- Enter LMP date (required if no conception date): Input the first day of your last period.
- Set average cycle length (default 28 days): Adjust between 20–45 days if your cycle differs.
- Optional: Enter conception date: If known, this overrides the LMP calculation.
- Click "Calculate" to see results.
Results show:
- Estimated Due Date
- Current Gestational Age (weeks + days)
- Days remaining until due date
Note: All dates use the MM/DD/YYYY format. Cycle length must be a whole number.
Previous Results
| Result | Inputs | Date |
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Frequently Asked Questions
ETG stands for Estimated Time of Gestation, which is the estimated length of pregnancy from the last menstrual period or conception.
Due date is calculated by adding 280 days (40 weeks) to the first day of the last menstrual period, adjusted for cycle length, or adding 266 days to the conception date.
Cycle length affects ovulation timing. A longer cycle shifts the due date later, while a shorter cycle shifts it earlier.
