Age Calculator
Calculate age from birthdate
Age Calculator: Calculate age from birthdate. A free, browser-based tool from DevToolbox that runs entirely on your own device: no upload, no account, no tracking.
About the Age Calculator
Free online age calculator. Calculate exact age in years, months, and days from birthdate. See next birthday countdown and total days lived. It is one of the time & date tools on DevToolbox, and like all of them it runs entirely in your browser.
Date handling uses the browser's own Date and Intl support, which means it knows your local time zone and the current daylight-saving rules without asking a server. Unix values are treated as seconds when they are 10 digits and milliseconds when they are 13.
What you can do with it
- Birthday calculator
- Calculate age
- How old am I
- Age in days
- Next birthday countdown
How to use it
- Enter the date, timestamp or duration you are working with.
- Every equivalent representation is listed at once: ISO 8601, UTC, local time and Unix values.
- Your local time zone is detected from the browser, so local values match your machine.
- Copy the representation you need.
Questions
- Is my data uploaded anywhere?
- No. The tool is JavaScript that runs in the tab you already have open, and DevToolbox has no backend to send anything to. You can open the network tab and watch: after the page and its script load, nothing is sent while you work.
- Does it work offline?
- Once the page has loaded, yes. The tool needs no network access to do its job, so it keeps working if your connection drops. Reloading the page does need the network unless your browser has it cached.
- Is it free, and do I need an account?
- It is free and there is no account, no sign-in and no usage limit. There is nothing to register because there is no server keeping track of anything.
Related tools
The Age Calculator sits in Time & Date, one of the 90 tools on DevToolbox.