Find your exact age as of today — in years, months, and days — plus a countdown to your next birthday. Just enter your date of birth.
Your age in full years is today's date minus your birth date, with the remaining months and days calculated from the last completed year.
Calculating exact age sounds simple but requires carefully counting full years, months, and days between two dates — accounting for varying month lengths and leap years. A naive subtraction of birth year from current year can be off by one whenever the current date falls before the birthday in the current year.
After determining full years, the remaining months and days are calculated from the most recent birthday to the current date, borrowing days from the previous month when needed — similar to how calendars handle month-length differences.
People born on February 29 (leap day) technically have a birthday only once every four years on the calendar. For practical and legal purposes, non-leap years typically treat either February 28 or March 1 as the observed birthday, depending on local convention.
| Unit | Approximate conversion |
|---|---|
| Years → Months | Years × 12 (+ remaining months) |
| Years → Weeks | Years × 52.18 |
| Years → Days | Years × 365.25 (accounts for leap years) |
| Years → Hours | Days × 24 |
Example 1 — Simple case: Someone born on 14 March 1990, calculated as of 13 August 2026, has already had their birthday this year. Full years = 2026 − 1990 = 36. Remaining time since 14 March is 4 months and 30 days, so the exact age is 36 years, 4 months, 30 days.
Example 2 — Birthday not yet reached: Someone born on 20 December 1995, calculated as of 13 August 2026, has not yet had their 2026 birthday. Years = 2026 − 1995 − 1 = 30. Counting back from 20 December 2025 to 13 August 2026 gives 7 months and 24 days, so the age is 30 years, 7 months, 24 days.
Example 3 — Leap-day birthday: Someone born on 29 February 2000 is, as of 13 August 2026, treated as having had their "birthday" on 1 March in non-leap years, so their age counts as 26 years and roughly 5 months even though only 6 actual leap-day anniversaries have occurred.
Why does simple year subtraction sometimes give the wrong age? It fails to account for whether the birthday has already occurred this year — subtracting years alone assumes it has, which isn't always true.
How is a February 29 birthday handled in non-leap years? Conventions vary, but many systems treat March 1 (or sometimes February 28) as the observed birthday in non-leap years.
Why do "days old" figures vary slightly between calculators? Small differences can come from how each tool handles leap years and rounding within the date range.
How many days old am I approximately, based on my age in years? Multiply your age in years by 365.25 to account for leap years, then adjust using the exact number of months and days since your last birthday for a precise figure.
Can this calculator find the age difference between two people? Yes — enter each person's date of birth and compare the two results; the difference between the two ages gives the gap between them.
What is a "chronological age" versus other age measures? Chronological age is simply the time elapsed since birth, as calculated here. It differs from concepts like "biological age," which estimates physical condition rather than elapsed time.
Why do some legal systems count age differently? A few countries historically used age-counting conventions that add a year at birth or count age up at New Year rather than on the birthday, which can differ from the calendar-based method used here.
How is age used in eligibility calculations, like for retirement? Eligibility rules typically require reaching an exact age (for example, 65 years) on or before a specific date, which is why precise year/month/day calculations matter more than a rounded age.
How do I calculate my exact chronological age? Enter your date of birth above — this chronological age converter instantly shows your exact age in years, months, and days as of today.
Someone born on July 20, 1990 calculated as of today (August 13, 2026) would be 36 years old, with their birthday having already passed this year — the calculator also shows the exact number of days until their next birthday.
Chronological age: Age measured strictly by elapsed calendar time since birth.