Pregnancy Due Date Calculator
Due date and trimester milestones from your last period.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Days until due date
- 210 days
- Gestational age
- 10 weeks 0 days
- Current trimester
- First trimester
- Progress
- 25%
Quick answer
Naegele's rule sets the due date 280 days after the first day of the last menstrual period, adjusted for cycle length.
Due date = LMP + 280 days
How to use the Pregnancy Due Date Calculator
- 1Count the days since your last period began.
- 2Enter your usual cycle length.
- 3Read the due date countdown and trimester.
Frequently asked questions
How accurate is the due date?
Only about 4% of babies arrive on the exact date; 80% arrive within two weeks either side.
What if my cycle is not 28 days?
The tool shifts the due date by the difference, since ovulation timing moves with cycle length.