Pregnancy Calculator – Estimate Your Pregnancy Week and Due Date

Just found out you're expecting? Our free Pregnancy Calculator helps you estimate how many weeks pregnant you are, your estimated due date, and your likely conception date, all based on your last menstrual period (LMP).

Pregnancy Calculator

Estimate your pregnancy timeline based on your LMP.

How to Use the Pregnancy Calculator

  1. Enter Your Last Menstrual Period (LMP): Select the first day of your last period from the calendar input fields (DD, MM, YYYY). This is the most crucial piece of information.
  2. Adjust Cycle Length (Optional): The calculator defaults to a 28-day cycle, which is the average. If your cycle is consistently longer or shorter, adjust this number for better accuracy.
  3. Click “Calculate”: Get your personalized pregnancy timeline instantly.

Understanding Your Results

Gestational Age

This tells you how many weeks and days pregnant you are. It's the primary way doctors track pregnancy progress.

Estimated Due Date

This is the projected date your baby will arrive, based on a 40-week gestation period.

Estimated Conception Date

This is the approximate date you likely conceived. It's typically about two weeks after your LMP.

Current Trimester

This shows which of the three trimesters of pregnancy you are currently in.

Pregnancy Weeks and Trimesters Explained

Pregnancy is typically measured in weeks, starting from the first day of your last menstrual period. A full-term pregnancy is about 40 weeks long. This duration is divided into three trimesters, each marking different stages of fetal development and changes in the mother's body.

  • First Trimester: Week 1 to Week 13. A period of rapid development for the baby.
  • Second Trimester: Week 14 to Week 27. Often called the "golden period" as many early pregnancy symptoms subside.
  • Third Trimester: Week 28 to Week 40+. The final stage of growth as the baby prepares for birth.

Our Gestational Age Calculator provides more week-by-week details.

Frequently Asked Questions