An age calculator is a tool that helps determine a person's or object's age based on the date of birth (or starting date) and the current date (or a specific date). It calculates the age usually in years, months, and days, and sometimes also in total days, weeks, hours, or even minutes and seconds. Users just input the birth date and the calculation date, then the tool gives the exact age or time elapsed between those dates. For example:

• You enter your birth date.
• The calculator then shows your age as years, months, and days, or total days you have lived.
• Some calculators also allow calculating age at a future or past date or finding out the age of an object or monument using the same concept.

There are also manual shortcut methods to calculate age quickly, such as subtracting birth year from current year and adjusting based on whether the birthday has passed in the current year. Many online age calculators provide instant results and detailed breakdowns and are useful for various applications like job applications, retirement planning, or curiosity. These tools are often free and easy to use with input fields or date pickers for birth date and calculation date.