Pregnancy Due Date Calculator

Calculate your estimated due date and pregnancy timeline

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First Day of Last Menstrual Period (LMP)

Frequently Asked Questions

How is the due date calculated?▼

Due date = Last Menstrual Period (LMP) + 280 days (40 weeks). This is known as Naegele's rule.

How accurate is the due date?▼

Only about 5% of babies are born on their exact due date. Most are born within 2 weeks before or after. The due date is an estimate.

How to Use Pregnancy Due Date Calculator

1Open the Pregnancy Due Date Calculator tool above - it loads instantly in your browser.
2Enter your data or upload your file. Everything is processed locally on your device - nothing is uploaded to any server.
3Get your results instantly. Copy, download, or share - completely free with no signup required.

Pregnancy Due Date Calculatoris part of BriskTool's collection of free online tools. All tools run entirely in your browser for maximum privacy and speed.