Exact calendar age
Years are counted birthday by birthday, then whole calendar months, then the remaining days — never by dividing days by 365. Months that are shorter than your birth day (say, the 31st) end on their last day.
Age calculator
Your exact age in years, months and days — counted on the calendar, birthday by birthday, never by dividing by 365.
Want the full picture? See every insight in Birthday Insights.
Exact age
ExactExampleYou've been here for
34years6months19days
That's 12,621 days. You were born on a Saturday, the 74th day of 1992.
Example: someone born on 14 March 1992, as of 3 October 2026. Enter your birthday above to see your own numbers.
Life in numbers
ExampleEvery unit of time you've lived.
Days, weeks and months are exact calendar counts. Hours, minutes and seconds assume you were born at midnight, because a date alone doesn't include a time.
12,621
days
Exact
1,803
weeks
Exact
414
calendar months
Exact
302,904
hours
Approximate · midnight convention
18.2 million
minutes
Approximate · midnight convention
1,090,454,400
seconds
Approximate · assumes 00:00 on your birth date
Your next birthday
ExactExampleYour next birthday
162days away
Sunday, 14 March 2027
You'll turn 35.
Same weekday as your birth
Your next birthday on a Saturday — the weekday you were born — is 14 March 2037.
Your next birthday is a Sunday, 162 days from today.
How it works
How your exact age is calculated
Your age in years is the number of birthdays you've reached. Then we count the whole calendar months since your last birthday, and finally the days since the last of those months began.
Calendar months have different lengths, so a simple “days ÷ 365” or “days ÷ 30” formula drifts. When your birth day doesn't exist in a shorter month — the 31st, say — that month's anniversary falls on its last day (31 January → 28 or 29 February).
Born on 29 February? In years without one, your birthday is observed on 28 February, and your age goes up that day. Your age is always your real calendar age — someone born on 29 February 2000 is 26, not 6.
| Date of birth | Exact age |
|---|---|
| 14 March 1992 | 34 years, 6 months, 19 days |
| 1 January 2000 | 26 years, 9 months, 2 days |
| 29 February 2000 | 26 years, 7 months, 4 days |
| 31 January 2010 | 16 years, 8 months, 3 days |
| 31 December 1965 | 60 years, 9 months, 3 days |
- Which time zone is used?
- Yours. “Today” is the calendar date on your device, so the result changes at your local midnight.
- Does it count the day I was born?
- Your birth day is day zero. On your first birthday you are exactly 1 year, 0 months and 0 days old.
- What dates are supported?
- Any real date from 1 January 1900 to today. Impossible dates, like 31 April or 29 February 1900, are rejected rather than adjusted.
- Is my birthday stored?
- No. It's calculated in your browser and forgotten when you close or reload the page.
Methodology
How the numbers are calculated
Every result is labelled: exact calendar arithmetic, an approximation that depends on a stated assumption, or an estimate based on an average.
Days, weeks and seconds
Days lived is the exact number of calendar days from your birth date to today in your own time zone. Hours, minutes and seconds assume you were born at midnight, because a date alone has no time.
Milestones
Milestone dates are your birth date plus an exact number of days, weeks (7 days), calendar months, or seconds. A billion seconds is about 31.7 years.
Leap years and 29 February
Gregorian rules: every 4th year is a leap year, except century years not divisible by 400 — so 2000 was a leap year, 1900 was not. A 29 February birthday is observed on 28 February in other years.
Around the Sun
Distance uses Earth's average orbit — about 940 million km per trip around the Sun. It's Earth's path relative to the Sun, so it's an estimate, not a precise measurement of your motion through space.
Moon cycles and body estimates
Lunar cycles use the average lunar month of 29.53 days. Heartbeats, breaths and sleep use fixed averages (72 beats/min, 15 breaths/min, 8 hours a night) — illustrations, not health information.
Supported dates: 1 January 1900 to today. Spotted something that looks wrong? Send feedback.
Privacy
Your birthday stays with you.
Core calculations happen directly in your browser. Birthday Insights does not require an account and does not save your date of birth.
Birthday Insights
- Calculates everything in your browser
- Keeps your birthday only while the page is open
- Lets you share a card without your birth date
Birthday Insights never
- Requires an account
- Saves your birthday in a database
- Puts your birthday in the page address
- Sends your birthday to analytics
Closing or reloading the page forgets your birthday. The site uses no cookies and no advertising or tracking scripts; if anonymous page-view counting is enabled, it uses cookie-free Cloudflare Web Analytics, which sees only which page was visited — never what you type.