Pregnancy Due Date Calculator
Estimate your due date and current week of pregnancy.
Frequently Asked Questions
What is Naegele rule?
It estimates the due date as 280 days (40 weeks) from the first day of the last menstrual period, equivalent to adding a year, subtracting three months and adding seven days. It assumes a regular 28-day cycle.
How accurate is a due date?
Only about 5 percent of babies arrive on their exact due date, though most arrive within a week either side. An early ultrasound scan can refine the estimate, especially with irregular cycles.
What if my cycle is not 28 days?
For longer cycles the due date usually falls later, and for shorter cycles earlier, by roughly the difference in cycle length. Mention your typical cycle length at your first appointment.
Is the Pregnancy Due Date Calculator free, and is my data private?
Yes. It is completely free and every calculation runs locally in your browser, so the numbers and dates you enter are never uploaded, stored, or shared with anyone.
Related Tools
Ovulation Calculator
Predict your ovulation day, fertile window and next period from your last period date and average cycle length, with dates for the following cycle too.
Date Add Calculator
Add or subtract days, weeks, months or years from any date and see the resulting date, its day of the week, and the total days between the two dates.
Age Calculator
Calculate exact age from date of birth in years, months, and days.
Days Until Calculator
Count the exact days, weeks and months until a future date or since a past date, perfect for countdowns to birthdays, holidays, deadlines and events.