An age calculator is a tool used to determine a person's age based on the date of birth. It is a simple and convenient way to find out one's age, without having to perform manual calculations. The user is required to input their date of birth and the calculator will automatically determine their age in years, months, and days. The age calculator can be used for a variety of purposes such as calculating the age of a person for a job application, determining eligibility for certain services or benefits, or for personal reasons such as planning for retirement or anniversaries.