Due date calculator
Enter the first day of your last period. We'll estimate your due date using the standard 280-day (40-week) rule — the same estimate Masik's Pregnancy mode uses once you're tracking with an account.
This is a general estimate from typical cycle math, not personalized medical advice — actual timing varies person to person and cycle to cycle. Nothing you enter here is saved unless you create a Masik account.
This is an estimate, not a diagnosis — actual due dates vary and should be confirmed with a doctor. Track your pregnancy week by week for free with a Masik account, or read what to expect in early pregnancy.