Pregnancy tool
Due Date Calculator
Enter the first day of your last period, your conception date or your IVF transfer date to estimate when baby will arrive, plus how far along you are right now.
This calculator gives an estimate. Only about 1 in 20 babies arrive on their due date, and your provider may adjust it after an ultrasound.
Common questions
How is my due date calculated?
Most providers add 280 days (40 weeks) to the first day of your last menstrual period, adjusted if your cycle is longer or shorter than 28 days. From conception, it is 266 days. For IVF, the calculation counts back from the embryo age at transfer.
How accurate is a due date?
It is an estimate. Most babies arrive within two weeks either side of it, and your provider may update the date after an early ultrasound.
When is a baby considered full term?
A pregnancy is considered full term from 39 weeks 0 days through 40 weeks 6 days.
