Estimate your baby's due date based on your last menstrual period.
Result
-
Estimated Due Date
Estimated Conception Date-
Current Week of Pregnancy-
Current Trimester-
Days Remaining-
Pregnancy Milestones
🫀 6-7 weeks pregnant — Heartbeat detectable
👋 16-20 weeks pregnant — First movements felt
⭐ 24 weeks pregnant — Viability milestone
✅ 37+ weeks pregnant — Full term
⚙️ How It Works
A due date calculator estimates when your baby will be born based on the first day of your last menstrual period (LMP) or conception date. The standard method (Naegele's Rule) adds 280 days (40 weeks) to the LMP. Only about 5% of babies are born on their exact due date — most arrive within two weeks before or after.
Due Date (Naegele's Rule) = LMP + 280 days | Alternatively: LMP + 9 months + 7 days | Gestational Age = (Current Date − LMP) in weeks
Editorial Standards
Author
BetterProduct Editorial Team - Editorial standards and multilingual quality review
Reviewed by
Reviewed against public due-date guidance and standard gestational timing conventions.
Updated
April 2026
Best used for
Pregnancy timeline estimates for planning conversations with a licensed clinician.
Languages checked
7 language editions aligned from the same source formulas.
Use Results Responsibly
Use these numbers as screening estimates, not as a diagnosis.
Age, sex, activity, medications, and medical conditions can change the right interpretation.
If you are pregnant, symptomatic, or managing a condition, confirm decisions with a licensed clinician.
Due dates are approximate. Ultrasound findings, cycle length, and clinical judgment can adjust the expected date.
Use these numbers as screening estimates, not as a diagnosis.
Age, sex, activity, medications, and medical conditions can change the right interpretation.
If you are pregnant, symptomatic, or managing a condition, confirm decisions with a licensed clinician.
❓ FAQ
How accurate is the due date calculation?
The calculated due date is an estimate. Only about 5% of babies are born on their exact due date. About 80% are born within two weeks of the due date. Ultrasound measurements in the first trimester provide the most accurate dating.
What are the trimesters of pregnancy?
The first trimester is weeks 1–12, the second is weeks 13–26, and the third is weeks 27–40. Each trimester brings different developmental milestones and physical changes. Full term is considered 39–40 weeks.
What is gestational age vs fetal age?
Gestational age counts from the first day of the last menstrual period (LMP), which is about 2 weeks before conception. Fetal age (conception age) counts from fertilization. Doctors use gestational age, so a 'week 6 pregnancy' is about 4 weeks after conception.
What is a premature birth?
A premature (preterm) birth occurs before 37 weeks of gestation. Babies born at 34–36 weeks are 'late preterm' and usually do well. Those born before 28 weeks face more significant challenges. Modern neonatal care has dramatically improved outcomes for premature babies.