BirthdayCalculating your age sounds simple until you try to do it precisely by hand. Most people know their age in years, but very few can quickly work out their exact age in years, months, and days without making a mistake - especially around leap years.
The basic method
Start by subtracting your birth year from the current year. Then compare the current month and day to your birth month and day. If the current month and day haven't yet reached your birth month and day, subtract one year from your running total.
Where people go wrong
The most common mistake is ignoring how many days are actually in the previous month when borrowing days, since months range from 28 to 31 days. February in a leap year adds another wrinkle, with 29 days instead of 28.
The easier way
Rather than tracking all these edge cases by hand, our free Age Calculator handles the leap-year logic and variable month lengths automatically, giving you an exact years/months/days breakdown in under a second.