Pregnancy Week Calculator

Use this free Pregnancy Week Calculator to estimate your current pregnancy week based on the first day of your last menstrual period (LMP). It helps you track pregnancy progress, trimester stages, and important milestones.

Enter your details below and click calculate to get instant results.

Pregnancy Week Calculator



What is a Pregnancy Week Calculator?

A Pregnancy Week Calculator helps estimate how many weeks pregnant you are based on the first day of your last menstrual period (LMP).

It helps track trimester progress, baby development, and important medical milestones during pregnancy.


How Pregnancy Weeks Are Calculated

Pregnancy is usually counted from:

The first day of your last menstrual period (LMP)

not from the conception date.

A full pregnancy is usually around:

40 weeks

Doctors commonly use this method for pregnancy tracking.


Pregnancy Trimesters

First Trimester

Week 1 to Week 12

Second Trimester

Week 13 to Week 26

Third Trimester

Week 27 to Delivery

Tracking your pregnancy week helps you understand which stage you are currently in.


Example

Last menstrual period:

January 1

Today:

March 1

Estimated pregnancy:

Around 8 weeks pregnant

This helps with medical appointments and baby planning.


Why Use This Calculator?

It helps with:

  • Tracking pregnancy progress
  • Understanding trimester stages
  • Preparing doctor visits
  • Monitoring baby development
  • Pregnancy planning

It gives a quick estimate without manual counting.


Important Note

This tool gives an estimate only.

Your doctor may adjust pregnancy dating using ultrasound scans for better accuracy.


FAQs

Common Questions

How many weeks is full-term pregnancy?

Most full-term pregnancies are around 40 weeks.


Why is pregnancy counted from LMP?

Because the exact conception date is often harder to confirm.


Can ultrasound change pregnancy week?

Yes. Doctors may adjust pregnancy dating based on scans.


Is this calculator accurate?

It provides a strong estimate, but medical confirmation is always best.


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