Age Calculator
Gives exact age in years, months and days from a date of birth, and the days until the next birthday.
Runs in your browser. The file or text you give it is not uploaded. Free, no account.
How it works
You need an exact age for a form, a record or a birthday, not a rough count of years. Enter a date of birth, and optionally another date to measure to. You get the age in calendar years, months and days, the totals in months, weeks, days and hours, and the days until the next birthday.
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Enter a date of birth and, if you want, a different date to measure to.
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The result counts calendar years, months and days the way people do, handling leap years and month lengths, and also gives the total in months, weeks, days and hours.
What it does not do
This calculator treats 1 March as the birthday in non-leap years for someone born on 29 February. Legal conventions vary.
When a source is busy or a site does not answer, this tool says so. It never fills the gap with a guess.
Questions
Why does a 29 February birthday count as 1 March in some years?
Because 29 February does not exist in non-leap years, so there is no matching calendar day to land on. This tool counts the birthday as 1 March in those years, which is this calculator's convention, not a universal legal rule. In a leap year the date is 29 February. If your country handles it differently, adjust the result by a day.
How is age counted: completed years or calendar years?
Calendar years, months and days, the way a person would count them. It handles leap years and varying month lengths, so 31 January to 1 March is counted as one month and one day rather than a flat number of days. You also get the total in months, weeks, days and hours if you need one figure.
Can I measure age at a date other than today?
Yes. Enter a date of birth and then a second date to measure to, for example a policy start date, an exam date or a date in the past. Leave the second field alone and it measures to today. The result gives the exact age at that date plus the days until the next birthday from it.