Enter your date of birth to see your exact age.
How Old Am I? Exact Age Explained
Your age is the number of whole years since your birth date, then whole months, then the days left over. Someone born on March 15, 1990 is 36 years, 6 months and 6 days old on September 21, 2026, or 13,339 days. Enter any birth date above to get the same breakdown plus totals in months, weeks, days, hours and minutes.
How the Calculator Counts Your Age
It works on calendar dates, the same way you would with a paper calendar. Take someone born on October 30, 1985 and count to September 21, 2026:
- Whole years. Count the birthdays already reached. The last one was October 30, 2025, the 40th.
- Whole months. From October 30, 2025 to August 30, 2026 is 10 full months.
- Remaining days. From August 30 to September 21 is 22 days.
Result: 40 years, 10 months and 22 days, which is 14,936 days in total. Dividing the day count by 365.25 gets close, but it can be a day off around a birthday, which is why the calculator never does it.
Month-end and leap day birthdays
When your birth day does not exist in a month, the calculator uses that month's last day. A baby born on January 31 is 1 month old on February 28 (February 29 in a leap year). A person born on February 29 has the birthday counted on February 28 in common years, so someone born on February 29, 2008 turned 18 on Saturday, February 28, 2026 by this count. Some laws and institutions use March 1 instead, so check the rule that applies when it really matters.
Days come from the calendar, not the clock
Total days are counted from calendar dates, so the one-hour daylight saving shifts in spring and fall never make the total a day short. Hours and minutes are the day total times 24 and times 1,440, measured from midnight on your birth date.
Days Old on Milestone Birthdays
How many days you have lived on the day you turn each age, for anyone born between 1926 and 2025. The figure depends on how many February 29ths fall in between, so most ages have two possible values.
| Birthday | Days old | Full weeks |
|---|---|---|
| 1st | 365 or 366 | 52 |
| 5th | 1,826 or 1,827 | 260 |
| 10th | 3,652 or 3,653 | 521 |
| 16th | 5,844 | 834 |
| 18th | 6,574 or 6,575 | 939 |
| 21st | 7,670 or 7,671 | 1,095 |
| 30th | 10,957 or 10,958 | 1,565 |
| 40th | 14,610 | 2,087 |
| 50th | 18,262 or 18,263 | 2,608 |
| 65th | 23,741 or 23,742 | 3,391 |
| 80th | 29,219 or 29,220 | 4,174 |
| 100th | 36,524 or 36,525 | 5,217 |
Your 10,000th day comes at about 27 years and 4 months, a milestone some people celebrate instead of a birthday.
US Age Milestones Worth Knowing
| Age | What changes |
|---|---|
| 18 | Voting age in all federal and state elections (26th Amendment) |
| 21 | Minimum legal drinking age in every state |
| 50 | 401(k) catch-up contributions allowed, $8,000 extra in 2026 ( 1,250 at ages 60 to 63) |
| 59½ | IRA and 401(k) withdrawals without the 10% early withdrawal penalty |
| 62 | Earliest age to claim Social Security retirement benefits (reduced) |
| 65 | Medicare eligibility |
| 67 | Full Social Security retirement age for anyone born in 1960 or later |
| 73 | Required minimum distributions begin for people born 1951 to 1959 (75 if born in 1960 or later) |
Social Security has its own counting rule: it treats you as reaching an age on the day before your birthday, and people born on the 1st of a month are treated as if born in the previous month. A person born on January 1, 1962 therefore reaches 65 on December 31, 2026 for benefit purposes. The Social Security calculator and 401(k) calculator build on these ages.