Pregnancy Calculator

This Pregnancy Calculator helps you estimate your pregnancy due date, current gestational age, and key pregnancy milestones based on the first day of your last menstrual period (LMP).

Pregnancy duration is calculated as 40 weeks (280 days) from LMP.

Pregnancy Details

Estimated Due Date
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Gestational Age
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Current Trimester
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How Pregnancy Due Date Is Calculated

Pregnancy due dates are commonly calculated using Naegele’s Rule, which assumes a 28-day menstrual cycle. The estimated due date is calculated as:

LMP + 280 days (40 weeks)

What Is Gestational Age?

Gestational age refers to how far along a pregnancy is, measured in weeks and days from the first day of the last menstrual period.

Pregnancy Trimesters

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

Important Pregnancy Milestones

  • Heartbeat detectable around 6–7 weeks
  • First movements felt around 16–20 weeks
  • Full-term pregnancy at 37 weeks+

Only about 5% of babies are born on their exact due date. Most deliveries occur within two weeks before or after the estimated date.

Frequently Asked Questions

Pregnancy calculators provide estimates. Ultrasound dating and medical evaluation provide more accurate results.
If your cycle is longer or shorter than average, your actual due date may vary slightly from the calculated estimate.
No. Gestational age starts from LMP, while fetal age begins at conception, about two weeks later.
A pregnancy is considered full term between 39 and 40 weeks.