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Free calculatorPregnancy Due Date Calculator
Estimate your due date in seconds — from your last period, conception date or IVF transfer. You will also see how many weeks pregnant you are today.
Frequently asked questions
How is the due date calculated?
Most due dates add 280 days (40 weeks) to the first day of your last period, adjusted for your cycle length. From conception it is 266 days; from a Day-5 IVF transfer, 261 days.
How accurate is a due date?
It is an estimate — only about 1 in 20 babies arrive on the exact date. Most are born within two weeks either side. Your doctor confirms dates with an early ultrasound.
Related
Note: These calculators give estimates for general guidance only and are not a substitute for medical advice. Your doctor confirms your dates and due date by ultrasound.