🎂 Age Calculator
Your age is more than a number on a birth certificate — it's the exact span of years, months and days since you were born, and knowing it precisely matters for official forms, age limits and milestone planning. Enter your date of birth and this calculator instantly works out your calendar age, broken down into years, months and days, plus the total number of days you've lived. Leap years and whether your birthday has already happened this year are accounted for automatically, so the result is always exact.
Formula
Age = today − date of birth, split into years, months and days
The calculator first subtracts the birth year from the current year for a provisional number of years. If your birthday hasn't happened yet this year, one year is subtracted and twelve months borrowed; the same borrowing happens at the day level if today's date falls earlier in the month than your birth date. This is exactly how you'd count age by hand on a calendar, which is why the result always matches official age calculations. The total day count is calculated separately, as the full number of calendar days between the two dates.
Steps
- 1Enter your date of birth in the date field.
- 2The calculator compares it with today's date.
- 3Read off your age in years, months and days, plus the total number of days lived.
Age in years converted to days and weeks
| Age (years) | Approx. days | Approx. weeks |
|---|---|---|
| 1 | 365 | 52 |
| 10 | 3,653 | 522 |
| 18 | 6,575 | 939 |
| 21 | 7,670 | 1,096 |
| 30 | 10,958 | 1,565 |
| 50 | 18,263 | 2,609 |
| 65 | 23,741 | 3,392 |
| 100 | 36,525 | 5,218 |
Based on an average year of 365.25 days (accounting for leap years); your exact age in days depends on how many leap years you've lived through.
commonMistakes
- Simply subtracting the birth year from the current year without accounting for whether the birthday has passed yet.
- Estimating age in days by multiplying years by 365 and forgetting leap years.
- Assuming age in 'complete years' equals the raw calendar-year difference, when that's only true once this year's birthday has passed.
useCases
- Checking your exact age for an official form.
- Determining eligibility for an age-restricted service, such as voting, driving or pension.
- Working out a child's exact age in months for medical check-ups or developmental milestones.