When is your due date?
Based on the first day of your last period, using the standard 280-day (40-week) estimate.
This is a general estimate based on a standard 40-week pregnancy and doesn't account for individual variation. Your healthcare provider's estimate, especially one based on an ultrasound, is more accurate.
How the pregnancy due date estimate works
This calculator estimates a due date by adding 280 days, or 40 weeks, to the first day of the last menstrual period. It is a standard calendar estimate and can also give a general indication of pregnancy progress.
Pregnancy timing varies, and an estimated due date is not a diagnosis or a substitute for prenatal care. A healthcare professional may adjust the estimate using cycle information, clinical assessment, or ultrasound findings.
Related tools: Create a personal countdown · Calculate days between dates
Frequently asked questions
How is the due date calculated?
We add 280 days (40 weeks) to the first day of your last menstrual period — the same method most standard pregnancy wheels and calculators use.
Is this accurate for everyone?
It's a general estimate. Cycle length and ovulation timing vary, so an ultrasound-based estimate from a healthcare provider is generally more precise.
General information only — not medical advice. For guidance about your pregnancy, speak with a qualified healthcare provider.