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Age calculator
Work out an exact age in years, months and days, and how long it is until the next birthday.
Your details
Enter a date of birth, and a date to measure to.
Defaults to today. Change it to work out an age on any date.
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Figures checked
This calculator is arithmetic only and uses no statutory figures. This is general information, not professional advice.
Why ages are fiddly
Calendar months are of different lengths, so an age in years, months and days cannot be worked out by dividing. The usual method, and the one used here, counts whole years first, then whole months, then the days left over, borrowing from the previous month when the day of the month has not yet been reached.
Leap years
Someone born on 29th February has no birthday in most years. In law, for most purposes in the United Kingdom, they are treated as having their birthday on 1st March in a common year. The day count here includes every leap day that has passed.