Birthday Calculator Online

Calculate age from your birthday. See exact age in years, months, days, total days and weeks.

Birthday (date of birth)

As of date (optional)

Leave empty for today

Birthday calculator online

Use the birthday calculator to find your age from your birthday. Enter your date of birth and optionally an as-of date to get age in years, months, days, total days and weeks.

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Age Calculator →Birth Date Calculator →Age Difference Calculator →

Cite This Calculator

Reference this calculator on your website or in your work using the citation below:

HTML Citation Code:

<p>Calculator: <a href="https://onlinecalculator.co.uk/time/birthday-calculator" target="_blank">Birthday Calculator Online</a> - OnlineCalculator.co.uk</p>

APA Style Citation:

OnlineCalculator.co.uk. (2025). Birthday Calculator Online. Retrieved from https://onlinecalculator.co.uk/time/birthday-calculator

Note: This calculator is free to use and reference. No permission required for educational or commercial citation.