Age Calculator
How old am I, exactly? Type your date of birth and this free age calculator tells you your precise age in years, months and days — plus total days lived, the weekday you were born, and a countdown to your next birthday. Everything runs 100% in your browser; your birthdate never leaves your device.
Pick the date from the calendar, or type it as YYYY-MM-DD.
100% client-side — nothing is uploaded or stored.
How to use it
Pick your birthdate in the date field (or type it as YYYY-MM-DD) and press Calculate age. The big headline shows your exact age — years, months, days — and the six stat cards break it down further: total days and weeks lived, approximate total hours, the weekday you were born on, and how many days remain until your next birthday, including the age you'll turn. Copy summary copies all of that as plain text for pasting into a form, message, or document.
What it expects
Just one thing: a valid date of birth, today or earlier. A future date gets a friendly error instead of a negative age, and a date more than 150 years ago gets a gentle "did you mistype the year?" warning rather than a suspicious result. The date is read in your own timezone, so the day you pick is the day that's used — no UTC-midnight shift stealing or adding a day.
How the math works
There are two honest ways to compute an age, and only one of them matches how humans talk about birthdays. The lazy way divides your total days alive by 365.25 — quick, but it produces answers like "32.47 years" that nobody uses. The calendar way counts the way you'd count on your fingers:
- Years: this year minus your birth year — then subtract one if your birthday hasn't happened yet this year.
- Months: this month minus your birth month (adjusted by the year borrow) — then subtract one if your birth day-of-month hasn't arrived yet this month.
- Days: the remaining days, borrowing the length of the previous month when needed — which is exactly where leap years are handled, because February's length comes from the real calendar.
So someone born on 15 March 1990 checking on 5 October 2026 is 36 years, 6 months and 20 days old — October minus March is 7 months, minus one because the 15th hasn't arrived yet this month (borrowing September's 30 days: 30 − 15 + 5 = 20). The calculator does this borrowing automatically, including the February 29 edge cases.
Common uses for an age calculator
- Forms and applications: school admissions, sports leagues, and ID applications often ask for age in years and months, not just years. Copy the exact figure instead of doing subtraction in your head.
- Eligibility checks: "must be 18 by 1 September" style cutoffs are really date arithmetic — run the birthdate through the calculator and compare.
- Milestones: the total-days and total-weeks counters turn round numbers into celebrations: 10,000 days old happens at about 27 years and 4–5 months.
- Fun facts: the weekday you were born and your next-birthday countdown are the two things people ask this page for most after the age itself.
Leap-year birthdays
Born on February 29? In leap years your birthday lands on the real date and everything is straightforward. In common years there's no February 29, so this calculator follows the most common convention and treats March 1 as your birthday for the countdown. Your years-months-days age is unaffected either way, because the calendar math borrows February's actual length for whatever year it's counting through.
Frequently asked questions
- How is my exact age calculated?
- By calendar math, not by dividing days by 365. The calculator takes today's date, subtracts your birth year, then adjusts: if your birthday hasn't happened yet this year it borrows a year, and if the day-of-month hasn't arrived it borrows a month — the same way you'd count it by hand. That's why the answer is exact years, months and days, leap years included.
- Why does my age differ by a day on some calculators?
- Usually a timezone bug: some calculators treat your birthdate as midnight UTC, which can shift it to the previous day in your timezone. This page parses your date in your own local timezone, so the date you pick is the date it uses — no silent shift.
- What day of the week was I born on?
- The result panel shows it automatically — the weekday of your birthdate, computed from the calendar. It's a fun detail people often want alongside their age, so it's included free.
- How does the birthday countdown work?
- It finds your next birthday from today's date and counts the days until it, along with the age you'll turn. If you were born on February 29, non-leap years count March 1 as your birthday — the most common convention — and the countdown says so.
- Can I calculate the age of someone else, or an age at a past date?
- You can enter any birthdate — a child's, a parent's, a historical figure's — and the calculator returns the age as of today. It always measures up to the current date; it doesn't take a custom "as of" date.
- Is there a maximum age the calculator accepts?
- Dates more than 150 years in the past trigger a gentle warning rather than a result, because that's almost always a typo (a wrong year typed into the date picker). The limit is our own sanity check, not a biological claim — verified supercentenarians have lived past 115.
- Is my birthdate uploaded anywhere?
- No. All calculations happen in your browser with JavaScript — your birthdate never leaves your device.