Age calculator.
Enter a birth date and read an exact age in years, months and days, with the totals and the next birthday. Counted on the calendar, in your browser.
Age calculator.
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3 steps, no account. It runs in your browser and nothing is uploaded.
Enter the birth date
Pick the birth date; the age as of today appears at once.
Choose the day, or a second person
Change the As of date to see the age on another day, or switch to Two people for a difference.
Read the details
Years, months and days, the totals, the next birthday and the weekday of birth.
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More math and finance. Every one free, in the browser.
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Questions and answers
Before you trust the result: what to know about the format, the limits, your data and the tools next to it.
On the calendar. Whole months are counted first, from the birth day to the same day of a later month, then the days left over, so someone born on 31 January is one month and one day old on 1 March, not 29 or 30 days. That is how a birthday card and most countries count it.
Their birthday is 1 March in years without a 29 February, which is how most countries treat it. The next-birthday line and the countdown follow that rule.
Days are counted between the two calendar dates, not between instants, so the clock change twice a year never makes a day 23 or 25 hours long. Weeks, hours and months follow from the days and the calendar count.
The tropical dates most horoscopes use: Aries from 21 March, Taurus from 20 April and so on. They are listed as a curiosity; the age is the point.
Enter the birth date and the age as of today appears, with the totals and the next birthday. Change the As of date to see the age on any other day: a document date, a future date, a historical one.
Switch the Mode to Two people and enter both birth dates. The difference is shown oldest first, counted the same way, with which date is the older.
No. The dates stay in your browser; the page makes no request with them. The arithmetic is a few lines of calendar code that run on your device.
No. The Age calculator is free and opens without a sign-in, an account or an install.
The Age calculator keeps nothing on a server; only the invoice generator saves its draft, in this browser's localStorage on your device. Nothing else is saved, and nothing is sent to shadcn.io.
Yes. The Two people mode takes both birth dates and shows the difference, oldest first, counted the same calendar way.
Change the As of date. The age is then worked out on that day, which suits a document date, a future date or a historical one.
It also lists totals for the age and the date of the next birthday, with the zodiac sign as a curiosity.
Closest to the Age calculator: Calculator, Time zone converter, Unix timestamp converter, Timer and stopwatch. Each opens on its own page, free and in the browser.
The Age calculator is one of 20 in its group. The group's page, /tools/math, lists them all.
The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.
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