How does the Due Date Calculator work?

The Due Date Calculator uses Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP), or add 266 days (38 weeks) to the conception date. This is the standard method used by OB/GYNs worldwide.

How accurate is the due date?

The due date is an estimate based on standard formulas. Only about 5% of babies are born on their exact due date. Most arrive within two weeks before or after. Always consult your healthcare provider for personalized guidance.

Completely safe. This tool is 100% client-side — all calculations happen in your browser. No personal data is collected or uploaded to any server.

Can I use this on mobile?

Yes. This tool is fully responsive and works on phones, tablets, and desktops.

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🤰 Due Date Calculator

Accurately calculate your due date and track pregnancy milestones

First Day of Last Period (LMP)

Avg. Cycle (days)

Standard 28-day cycle. Adjust if your cycle is irregular.

Conception Date

Embryo Transfer Date

Embryo Type

What is Due Date Calculator - Calculate Pregnancy Due Date & Gestational Age?

Due Date Calculator - Calculate Pregnancy Due Date & Gestational Age is a free online tool that runs entirely in your browser. No download or signup needed — enter Avg. Cycle and Conception Date to get results instantly. All data is processed locally.

Use Cases

Track health metrics when monitoring personal wellness
Adjust fitness plans based on calculated results
Interpret medical checkup reports with accurate numbers
Quick access on mobile without installing health apps

Key Features

Completely Free: No registration, no limits
Privacy Safe: Data never leaves your browser
Cross-Platform: Any modern browser
Zero Dependencies: Open and use

📋 Pregnancy Milestones

What is Due Date Calculator - Calculate Pregnancy Due Date & Gestational Age?

Use Cases

Key Features