Estimate your due date and current gestational age from the first day of your last menstrual period, with a live countdown.
Pregnancy dates are estimates. Pregnancy length, ovulation timing and delivery dates can vary. This tool is not medical advice.
The estimated due date is calculated as 280 days (40 weeks) from the first day of the last menstrual period. Gestational age is measured from that same reference date.
Example
A due date is an estimate, not a prediction of the exact delivery date. Ovulation, cycle length and individual pregnancy factors can change the timing.
Why 280 days and not exactly 9 months?
280 days (40 weeks) counted from the first day of your last period is the standard clinical convention — it's a bit longer than a literal "9 months" because pregnancy is dated from your last period, not from conception. Your actual delivery date is still an estimate, not a guarantee.
The estimated due date is calculated by adding 280 days (40 weeks) to the first day of the last menstrual period (LMP).
Example: If the LMP date is January 1, the estimated due date is October 8 in a non-leap year.
This is an estimate for informational purposes. Actual pregnancy dating can differ, and a qualified healthcare professional can provide individualized guidance.
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