Pregnancy Due Date Calculator

Calculate your estimated due date based on your last menstrual period

Calculate Your Due Date

First day of your last menstrual period (LMP):

How the Calculator Works

This pregnancy due date calculator uses the Naegele's Rule, which is the standard method used by healthcare providers to estimate your due date. The calculation adds 280 days (40 weeks) to the first day of your last menstrual period (LMP).

The Formula:

Due Date = First day of LMP + 280 days (40 weeks)

Keep in mind that only about 5% of babies are born on their exact due date. Most babies are born between 37 and 42 weeks of pregnancy. Your due date is an estimate to help you and your healthcare provider track your pregnancy progress.

Accuracy Factors

While our calculator uses standard medical formulas, several factors can influence the exact timing of your baby's arrival:

•Cycle Length: This calculation assumes a standard 28-day menstrual cycle.
•Irregular Cycles: If your cycles are shorter or longer, the LMP method may be less accurate.
•Ultrasound Dating: Early ultrasounds (before 12 weeks) are considered the most precise way to date a pregnancy.
•Medical Adjustments: Your doctor may adjust your due date based on physical exams or scan results.

Healthcare professional explaining pregnancy accuracy

When Babies Arrive

Understanding the window of birth can help you prepare for the big day:

•Full Term: A pregnancy is considered full term anywhere between 37 and 42 weeks.
•The 5% Rule: Only about 5% of babies are actually born on their estimated due date.
•The Window: Over 80% of babies arrive within two weeks (before or after) of their due date.
•First-Time Moms: Statistics show that first babies often arrive a few days after the due date.

Your Pregnancy Timeline

First Trimester

Weeks 1-12

Major organs form, morning sickness common, first prenatal visits, hear baby's heartbeat

Second Trimester

Weeks 13-26

Feel baby move, anatomy scan, find out gender (optional), energy returns, baby bump visible

Third Trimester

Weeks 27-40

Baby gains weight, prepare nursery, pack hospital bag, attend childbirth classes, meet your baby!

Track Your Journey

Get personalized updates, track milestones, and access expert guidance with BabyBloom.

Download BabyBloom App

Medical Disclaimer

This calculator provides an estimate only. Your healthcare provider will give you a more accurate due date based on ultrasound measurements and other factors. Always consult with your doctor for personalized medical advice.