Pregnancy Week Calculator
Enter an estimated due date to calculate the approximate pregnancy week and day today, estimated last menstrual period, estimated conception date and the number of days remaining. This timeline is for general educational use because pregnancy dating may be revised by clinical assessment.
How to use the Pregnancy Week Calculator
- Enter the estimated due date supplied by a healthcare professional or another dating calculation.
- The calculator counts backward 280 days to estimate the last menstrual period date.
- It counts backward approximately 266 days to estimate conception.
- Current estimated gestational age is calculated from the difference between today and the due date.
- The countdown displays remaining days or days beyond the estimated due date.
- These are calendar estimates and do not replace prenatal care.
Examples
Week and day display
A gestational age of 171 days is displayed as 24 weeks and 3 days.
Due-date countdown
A due date 30 calendar days in the future produces an estimated countdown of 30 days.
Frequently asked questions
How are pregnancy weeks counted?
Clinical gestational age is conventionally counted from the first day of the last menstrual period rather than from conception.
How many weeks is a typical pregnancy due-date estimate?
The conventional estimate is 40 weeks from the first day of the last menstrual period.
Why is conception estimated around two weeks after LMP?
The traditional dating system begins before conception because gestational age is counted from the last menstrual period.
Can the pregnancy week be different after ultrasound?
Yes. Clinical assessment may revise pregnancy dating.
Does this calculator provide medical advice?
No. It provides calendar estimates for general information.
What happens after the due date passes?
The calculator reports the number of days beyond the estimated due date, but medical management must be determined by a healthcare professional.
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