❤️ Health & Lifestyle
Due Date & Pregnancy Calculator
Calculate your estimated due date, current pregnancy week, trimester, and key milestones.
How the Due Date Calculator works
The calculator uses Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). If your cycle differs from 28 days, the cycle length adjustment corrects the LMP date. If you know your conception date, 266 days (38 weeks) are added instead. The current pregnancy week and trimester are calculated from today's date relative to your LMP.
⚕️ This tool is for informational purposes only. Always confirm your due date with a qualified healthcare professional or ultrasound scan.
Frequently Asked Questions
People also ask — answers optimized for search engines and voice queries.
How is the due date calculated?
The standard method uses Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). If you know your conception date, 266 days (38 weeks) are added instead.
How accurate is an estimated due date?
Only about 5% of babies are born exactly on their due date. Most births occur within 2 weeks before or after the estimated due date. An early ultrasound scan (dating scan) provides the most accurate dating.
What trimester am I in?
The first trimester covers weeks 1–12, the second trimester weeks 13–26, and the third trimester weeks 27–40. Most ultrasound dating scans happen in weeks 8–12.
My cycle is not 28 days — does that affect the due date?
Yes. For cycles shorter than 28 days, your due date is earlier; for longer cycles, it is later. Select your average cycle length in the calculator for an adjusted estimate.
Is this due date calculator free?
Yes, the Due Date Calculator on Potential Daily is completely free with no sign-up required.