How accurate is the pregnancy due date calculator?

The calculator provides an estimate based on standard 40-week pregnancy duration. However, only about 5% of babies arrive on their exact due date. Most babies are born within 2 weeks before or after the estimated date. Ultrasound measurements in early pregnancy can provide more accurate dating.

What is the difference between LMP and conception date methods?

LMP (Last Menstrual Period) method counts from the first day of your last period and is the standard medical approach. Conception date method counts from when fertilization occurred (usually 2 weeks after LMP). LMP is more commonly used as most women know this date more accurately.

When does pregnancy actually start?

Medically, pregnancy is counted from the first day of your last menstrual period, even though conception typically occurs about 2 weeks later. This is because the LMP date is more reliably known than the exact conception date.

What if my cycle is irregular?

If you have irregular cycles, the LMP method may be less accurate. In this case, early ultrasound dating (usually done between 8-13 weeks) provides the most accurate due date. Consult your healthcare provider for personalized assessment.

Can my due date change?

Your healthcare provider may adjust your due date based on ultrasound measurements, especially if done in the first trimester. Early ultrasounds (before 13 weeks) are most accurate for dating. Once established, the due date typically doesn't change unless there's significant medical reason.

What is considered full-term pregnancy?

Full-term pregnancy is now classified into categories: Early term (37-38 weeks), Full term (39-40 weeks), Late term (41 weeks), and Post term (42+ weeks). Babies born between 37-42 weeks are generally considered full-term.

How long is each trimester?

First trimester: Weeks 1-13, Second trimester: Weeks 14-27, Third trimester: Weeks 28-40. Each trimester is approximately 13-14 weeks long and marks different stages of fetal development.

Should I rely solely on this calculator?

This calculator is a helpful tool for estimation, but always consult with your healthcare provider for medical advice and accurate dating. They will use ultrasound and other clinical assessments to provide the most accurate due date and monitor your pregnancy health.

Pregnancy Due Date Calculator

Free online pregnancy calculator to estimate your due date and track pregnancy milestones. Calculate based on last menstrual period (LMP) or conception date with accurate trimester breakdown and weekly pregnancy timeline.

Calculate

Calculation Method

Last Menstrual Period (LMP)

Conception Date

First Day of Last Period

Pregnancy Timeline

Enter your date and click calculate to see your pregnancy timeline

Pregnancy Due Date Calculator Tool Introduction

Welcome to our free Pregnancy Due Date Calculator - the most comprehensive online tool for expectant mothers to calculate their estimated delivery date and track every stage of pregnancy. Whether you're newly pregnant or planning ahead, our medically accurate calculator helps you understand your pregnancy timeline from conception to delivery.

This pregnancy calculator uses two proven methods: the Last Menstrual Period (LMP) method, which is the standard approach used by obstetricians worldwide, and the conception date method for those who know their exact fertilization date. Simply enter your date, and instantly receive a complete pregnancy timeline including your current week, trimester information, and important milestone dates.

Perfect for first-time mothers, pregnancy planning, prenatal appointment scheduling, and understanding your baby's development week by week. Our calculator provides essential information including estimated conception date, first trimester end (week 13), second trimester end (week 27), third trimester milestones, and your estimated due date. Track your pregnancy journey with confidence using calculations that follow standard obstetric guidelines trusted by healthcare professionals globally.

Stay informed about your pregnancy progress, plan for important prenatal visits, and prepare for your baby's arrival with accurate, easy-to-understand pregnancy timeline information. All calculations are performed instantly in your browser with complete privacy - no registration or personal information required.

Pregnancy Due Date Calculator User Guide

Getting Started

Using the Pregnancy Due Date Calculator is simple and provides instant results:

Calculation Methods

Last Menstrual Period (LMP): Most common method - enter the first day of your last period
Conception Date: If you know when conception occurred, use this for more precise calculation

How to Use

Select Calculation Method: Choose between LMP or conception date
Enter Date: Input the relevant date using the date picker
View Results: Instantly see your due date and pregnancy timeline

Understanding Your Results

Due Date: Estimated delivery date (40 weeks from LMP)
Current Week: How many weeks pregnant you are today
Current Trimester: Which trimester you're currently in
Conception Date: Estimated date of conception
First Trimester End: End of week 13
Second Trimester End: End of week 27
Days Until Due Date: Countdown to your estimated delivery

Pregnancy Trimesters

First Trimester: Weeks 1-13 (Early development, morning sickness common)
Second Trimester: Weeks 14-27 (Energy returns, baby movements felt)
Third Trimester: Weeks 28-40 (Final growth, preparation for birth)

Important Notes

Due dates are estimates - only 5% of babies arrive on their exact due date
Full-term pregnancy is 37-42 weeks
Regular prenatal care is essential throughout pregnancy
Consult your healthcare provider for personalized medical advice
Ultrasound dating may provide more accurate estimates

Frequently Asked Questions

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