Pregnancy

Due Date Calculator

Calculate your baby's due date from your last menstrual period (LMP) or conception date using Naegele's Rule.

Input Parameters

Results

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Estimated Due Date

Pregnancy Week Today—

Trimester—

Current Month—

Days Until Due—

Calculating Your Due Date

Naegele's Rule: Due Date = LMP + 280 days (40 weeks). IVF Day-5 transfer: add 261 days. Only about 5% of babies arrive exactly on the due date. Your doctor may adjust the EDD based on ultrasound measurements in the first trimester.

⚕️ Always confirm your due date with your healthcare provider.

What is the Due Date Calculator?

The Due Date Calculator is a fast and accurate tool to predict the exact day you will give birth. Whether you are using your last period date, conception date, or an IVF transfer date, this tool will establish your medical timeline.

How It Works (Formula)

Obstetricians traditionally use Naegele's Rule to calculate an estimated due date (EDD). The formula takes the first day of the last menstrual period, adds one year, subtracts three months, and adds seven days.

$$ \text{EDD} = \text{LMP} + 7 \text{ days} - 3 \text{ months} + 1 \text{ year} $$

Naegele's Rule for standard 28-day cycle gestation prediction.

How to Use It

Select the calculation method (LMP, ultrasound date, or conception date), enter the relevant date, and click calculate. The tool will output your official estimated due date (EDD) to share with your doctor.