Pregnancy Week Calculator

Free pregnancy week calculator. Enter your last menstrual period to find out how many weeks pregnant you are, your trimester, and your estimated due date.

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Current Week hesaplanacak
Trimester hesaplanacak
Days Until Due Date hesaplanacak
Next Milestone hesaplanacak

How Pregnancy Weeks Are Counted

Pregnancy is counted from the first day of your last menstrual period (LMP), even though conception typically occurs about 2 weeks later. A full-term pregnancy is 40 weeks (280 days). Weeks are grouped into trimesters:

  • First trimester: Weeks 1–12
  • Second trimester: Weeks 13–26
  • Third trimester: Weeks 27–40

What This Calculator Shows

  • Current pregnancy week and day
  • Current trimester
  • Estimated due date (EDD)
  • Weeks remaining until due date
  • Key milestones for the current week

Key Pregnancy Milestones

WeekMilestone
Week 6Heartbeat detectable by transvaginal ultrasound
Week 10NIPT (non-invasive prenatal testing) available
Week 12First trimester screening / nuchal translucency scan
Week 18–20Anatomy scan (gender can be revealed)
Week 24Viability — baby can survive outside womb with intensive care
Week 28Third trimester begins; Rh antibody test
Week 37Early term — baby considered full term at week 39
Week 40Estimated due date

Gestational Age vs Fetal Age

Gestational age (counted from LMP) is typically 2 weeks more than fetal age (counted from conception). Doctors universally use gestational age when discussing pregnancy milestones and due dates.

How to Use This Calculator

Using our calculator is simple: enter the required values into the input fields and click the calculate button. Results are displayed instantly on screen. You can adjust the values and recalculate to compare different scenarios and find the best option for your situation.

Frequently Asked Questions

QuestionAnswer
How accurate are the results?We use standard formulas and up-to-date 2025 rates. Individual circumstances may vary slightly.
Is this calculator free?Yes, completely free and no registration required.
What should I do for exact figures?For precise information, consult a relevant professional or official authority.
Does it work on mobile devices?Yes, it works seamlessly on all devices and screen sizes.

Important Notes

This calculator is provided for informational purposes only. For legal, financial, or medical decisions, always seek advice from qualified professionals. Calculation results do not constitute official documents. Legislative changes may affect results; please visit the relevant official website for the most up-to-date information. Our calculators are regularly updated to reflect current regulations and rates.

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Frequently Asked Questions

Gestational age counts from the first day of the last menstrual period — about 2 weeks before conception. So "4 weeks pregnant" means roughly 2 weeks since conception.
First trimester: weeks 1-12. Second trimester: weeks 13-26. Third trimester: weeks 27-40. Full term is 37-40 weeks.
The anatomy scan checks the baby's organs, measurements, and development. It can also reveal the sex of the baby if desired.