Date of Birth Calculator

If someone is exactly 25 years old today, their birth date would be today's date 25 years ago. However, without knowing the exact birthday, you can only narrow it to the current year minus their age.

Yes — set the end date to today and the start date to the approximate past date. Adjust the start date until the difference matches your target number of days.

Common uses include filling out forms when only age is known, verifying eligibility for age-restricted activities, calculating insurance or benefit start dates, and genealogy research.