Free date of birth (DOB) calculator — find your exact age in years, months, days, and hours from any birth date. See how many days old you are, your total weeks lived, and your next birthday countdown.
This date of birth (DOB) calculator counts the full years, months, and days between your birth date and today (or any reference date you choose). It also tells you how many days old you are in total — useful for everything from school enrolment requirements to insurance forms.
| Field | What It Means |
|---|---|
| Years | Number of complete calendar years since birth |
| Months | Additional full months after the last birthday |
| Days | Remaining days after counting full months |
| Total Days Lived | Exact number of days from birth to reference date |
| Total Weeks | Total days divided by 7 (rounded down) |
| Total Hours | Total days multiplied by 24 |
| Next Birthday | Date and days remaining until the next birthday |
| Age | Days Lived (approx.) | Common Milestone |
|---|---|---|
| 1 year | 365 days | First birthday |
| 5 years | 1,826 days | Starting school |
| 10 years | 3,652 days | 10,000 hours milestone |
| 18 years | 6,570 days | Legal adulthood (most countries) |
| 21 years | 7,665 days | Legal adulthood (USA) |
| 25 years | 9,131 days | Quarter century |
| 40 years | 14,610 days | Over 1 million hours lived |
| 50 years | 18,262 days | Half century |
| 65 years | 23,741 days | Retirement age (many countries) |
| 100 years | 36,524 days | Centenarian |