Due Date Calculator
Calculate your pregnancy due date instantly based on LMP, conception date, or IVF transfer.
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Calculation Results
Your Estimated Due Date
March 31, 2027
Book your first prenatal appointment! Most clinics schedule the first ultrasound check between weeks 8 and 12.
Milestone Schedule
Estimated Conception
July 8, 2026
First Trimester Ends
September 23, 2026
Second Trimester Ends
December 30, 2026
Estimated Delivery Date
March 31, 2027
Metrics Analysis
How This Calculator Works
Naegele's Rule estimates the due date by assuming a standard 280-day gestational duration from the first day of your last period, adjusted dynamically for custom cycle lengths.
Pregnancy Due Date Calculator — Fast & Medically Accurate
Discover when your baby is due with our free, science-backed due date calculator. Supporting multiple methods including LMP, conception date, and IVF transfer milestones.
How to Calculate Your Estimated Due Date (EDD)
To calculate your due date, clinicians typically add 280 days (40 weeks) to the first day of your last menstrual period (LMP). If you have irregular cycles, our slider lets you adjust cycle lengths, automatically adding or subtracting offset days to improve dating precision.
Ultrasound vs. Conception Date Calculations
When conception or IVF dates are known, pregnancy duration is estimated as 266 days from fertilization. For ultrasound scans, the fetal crown-rump length (CRL) or head circumference determines gestational age, letting us project the remaining days to 40 complete weeks.
Clinical Standard Reference Guideline:
ACOG Committee Opinion No. 700: Methods for Estimating the Due Date.
Frequently Asked Questions (FAQ)
Q:How accurate is the estimated due date?
Only about 4% to 5% of babies are born on their exact due date. Most babies arrive between 37 and 42 weeks of pregnancy.
Q:Can my estimated due date change?
Yes, your healthcare provider may adjust your due date if an early ultrasound (dating scan) shows a significant size difference compared to your LMP calculation.
Q:What is Naegele's Rule?
It is a standard method: add 1 year, subtract 3 months, and add 7 days to the first day of your last menstrual period (LMP).