Age Calculator: How Old Am I?
Your exact age in years, months and days, and how long until your next birthday.
Runs entirely in your browser
Loading the tool…
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Enter a date of birth and the age is worked out as people count it: whole years, then the months since the last birthday, then the days. Beneath it are the same age in months, weeks and days, how long until the next birthday and which birthday it will be, and the day of the week you were born on.
Change Age on to work out an age on any other day, for a form that asks how old someone was on a given date. Someone born on 29 February has their birthday on the 28th in other years. Nothing you enter leaves this page.
How to use it
- Enter the date of birth.
- Leave Age on as today, or change it to another day.
- Read the age, and the next birthday beneath it.
Questions
How is age calculated?
In whole years first, the birthdays that have passed, then the whole months since the last one, then the days left over. That is how age is counted on forms and in law, and it is what this page shows.
What if I was born on 29 February?
Your birthday is taken as 28 February in years without a 29th, which is the usual rule. The next birthday shown follows it.
Is anything sent anywhere?
No. The dates are worked out in this tab, in WebAssembly, by a page that is not allowed to open a network connection. Nothing you type is stored or sent.
Other date questions
The same calculator, opened on another question. All four are a tap away on each.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.
This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.