Pregnancy Due Date Calculator
Estimate your due date, how many weeks pregnant you are, and your current trimester — all from the first day of your last period.
Your estimated due date will appear here.
What is a Pregnancy Due Date Calculator?
A Pregnancy Due Date Calculator estimates when your baby is likely to arrive. It uses the widely accepted Naegele’s rule, which adds 280 days — 40 weeks — to the first day of your last menstrual period (LMP) to give an estimated due date.
Alongside the due date, the tool shows how many weeks and days pregnant you are today and which trimester you are currently in, so you can follow your progress week by week.
An Estimate, Not a Guarantee
Only around one in twenty babies is born on the exact due date, and an early ultrasound may adjust the estimate. This calculator is a helpful guide, but it does not replace advice from your doctor or midwife.
How to Use It
Find your LMP date
The first day of your most recent period.
Enter it in the calculator
Select the date using the picker.
Get your estimate
See your due date, current week and trimester.
Benefits
Due Date
Know when to expect baby.
Track Weeks
See how far along you are.
Private
Nothing is stored.
Free
No sign-up needed.