How It Works
Pregnancy Due Calc helps you estimate your due date based on widely accepted medical methods. Below, we explain the options and what you should know.
1. Last Menstrual Period (LMP) Method
This is the most common and widely used method to estimate your due date. It works by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).
This method assumes a regular 28-day cycle, with ovulation occurring around day 14. If your cycles are longer, shorter, or irregular, this estimate may be less accurate.
Our online calculator uses this standard LMP-based method to give you an estimated due date.
2. Ultrasound-Based Dating
If your cycles are irregular, your LMP is uncertain, or your doctor recommends it, an ultrasound scan is used to estimate your due date more accurately.
- First Trimester Ultrasound: Typically performed between 8-12 weeks of pregnancy. Most accurate for dating.
- Second Trimester Ultrasound: Can still estimate due date, but may be less precise than early scans.
Ultrasound-based dating is considered the gold standard if available and recommended by your healthcare provider.
Important Notes
The due date provided by this website is an estimate only. Most pregnancies do not result in delivery on the exact due date. Full-term pregnancy is considered between 37 and 42 weeks.
Always consult your doctor or midwife for personalized care and to confirm your due date using the most appropriate method for your situation.
Why Estimate Your Due Date?
Knowing your estimated due date helps you and your healthcare provider plan for important prenatal check-ups, screenings, and preparations for childbirth.
Medical Disclaimer
This website provides general information only and is not a substitute for professional medical advice. Always consult your healthcare provider for guidance tailored to your health and pregnancy.