Age Calculator

How old are you, exactly?

Enter your date of birth and get your exact age in years, months and days — plus total days lived, the weekday you were born and the countdown to your next birthday.

  • Free forever, no sign-up
  • Dates never leave your browser
  • Leap-day & month-end rules handled
  • Age gap & any-date modes

Calculate your exact age

Pick the date from the calendar or type it as YYYY-MM-DD.

Privacy you can verify, not just trust

A date of birth is personal data, and most age calculators send it to a server to do the maths. This one can't: the calculation runs entirely in your browser. Your dates of birth are never sent anywhere — the only requests to other sites are the site's own analytics, which count page views. Nothing you type is stored, uploaded or shared. Don't take our word for it:

External requests during use: 0
  1. Press F12 to open developer tools, then the Network tab.
  2. Calculate any age above. Watch: apart from the site's analytics, no request fires at all — the answer is computed on your device.
  3. Extra credit: disconnect your internet after this page loads — the calculator still works.

How to calculate your exact age in years, months and days

Subtracting one year from another gives the age you reach that year — not your age today. Someone born in 1991 is not automatically 35 in 2026: if their birthday is in December, they are still 34 for most of the year. An exact age has to be counted on the calendar, in three passes from the largest unit to the smallest.

The counting method: years, then months, then days

Step 1 — whole years. Find the last birthday on or before the date you are measuring to. The number of that birthday is the age in years. If your birthday has not happened yet this year, your age in years is last year's number.

Step 2 — whole months. Starting from that last birthday, step forward one month at a time on the same day number until one more step would pass the date. The number of steps is the age in months.

Step 3 — days. Count the days from the last month mark to the date. That remainder is the age in days. This calculator shows these three steps under every result, so you can check its working.

Worked examples

Example 1 — a straightforward birthday. Born 15 March 1991, measured on 10 November 2026. The 35th birthday was 15 March 2026. Seven month marks later is 15 October 2026, and 26 more days reach 10 November. Exact age: 35 years, 7 months, 26 days — 13,024 days lived.

Example 2 — a leap-day birthday. Born 29 February 2000, measured on 10 November 2026. 2026 is not a leap year, so the 26th birthday counts on 28 February 2026. Eight month marks later is 28 October, and 12 more days reach 10 November. Exact age: 26 years, 8 months, 12 days — 9,751 days lived.

Example 3 — born on the 31st. Born 31 January 1990, measured on 10 November 2026. The 36th birthday was 31 January 2026. The month steps run 28 February (February has no 31st), 31 March, 30 April, 31 May, 30 June, 31 July, 31 August, 30 September and 31 October — nine months — and 10 more days reach 10 November. Exact age: 36 years, 9 months, 10 days — 13,432 days lived.

Example 4 — the age gap between two people. Born 12 June 1988 and 3 September 1995. Count from the earlier birthday: seven years to 12 June 1995, two months to 12 August, and 22 days to 3 September. Age gap: 7 years, 2 months, 22 days — 2,639 days.

Month-end and leap-year rules

Months are not all the same length, and that is where most age calculators go wrong. When the birth day number does not exist in a month — the 31st in April, June, September or November, the 30th or 31st in February — that month completes on the month's last day, and the next month mark returns to the original day number. So a 31 January birthday completes a month on 28 February (29 February in a leap year), then on 31 March.

A leap year has 366 days: every year divisible by 4, except century years, which must also be divisible by 400. So 2000 and 2024 are leap years, but 1900 and 2100 are not. A 29 February birthday counts on 28 February in common years in this calculator — the most widely used convention. In a leap year it falls on the real 29 February. If an official form or legal rule states otherwise (some use 1 March), follow the authority, not the calculator.

All counting uses the Gregorian calendar and whole calendar days. The time of birth and time zones do not change the answer: two people born on the same date have the same age in years, months and days wherever they live. The hours, minutes and seconds in the totals assume birth at midnight and 24 hours per day — they are the day total multiplied out, not a measured elapsed time.

Mistakes people make when working out an age

Subtracting the years only

2026 minus 1991 is 35, but that is only correct after the birthday. Before it, the answer is 34. Always check whether this year's birthday has passed.

Dividing total days by 365

13,024 days divided by 365 is 35.68 years — close, but it hides the months and days and drifts by a day for every leap year in between. Count on the calendar instead.

Treating every month as 30 days

A "month" is not 30 days: February has 28 or 29, seven months have 31. A 30-day month puts the answer out by up to three days per year.

Forgetting the leap day

Every leap year adds a day to the total days lived. Over 35 years that is eight or nine extra days — enough to change the day count and, near a birthday, the month count too.

Counting a birthday on 1 January

Age changes on your birthday, not on New Year's Day. The year count only increases on the anniversary of the birth date.

Confusing calendar age with legal age

This calculator gives chronological age — the calendar interval between two dates. Legal ages (school entry, driving, retirement) use their own rules and cutoff dates; check the authority's rule before relying on the number.

What the extra modes are for

Age on any date answers "how old will I be on…" — an application cutoff, a school enrolment date, a driving-test date, or a past anniversary. Enter the date you want to measure to instead of today and the same three-step count runs against it. Age gap compares two birthdays: parents checking the gap between siblings, or anyone settling "how much older is she, exactly?" — in years, months, days and total days. The live ticker on the Exact age tab keeps counting after you calculate, so the seconds total keeps moving while the page is open.

Frequently asked questions

How do I calculate my exact age in years, months and days?

Count in three steps, largest unit first. First count whole years: the number of birthdays that have passed by the date you are measuring to. Then count whole months from the last birthday, stepping month by month on the same day number. Finally count the days left over. For example, someone born on 15 March 1991 is 35 years, 7 months and 26 days old on 10 November 2026: the 35th birthday was 15 March 2026, seven month marks later is 15 October, and 26 more days reach 10 November. This calculator does the three steps for you and shows its working under every result.

What happens if I was born on 29 February (a leap day)?

This calculator counts a 29 February birthday on 28 February in common (non-leap) years, which is the most common convention. So someone born on 29 February 2000 turned 26 on 28 February 2026, and is 26 years, 8 months and 12 days old on 10 November 2026. In a leap year the birthday falls on the real 29 February. Note that some calculators and some legal systems use 1 March instead — if an official form asks, use the rule the authority states.

How is my age counted if I was born on the 31st of a month?

When the birth day number does not exist in a month, that month completes on the month's last day. Someone born on 31 January 1990 completes one month on 28 February 2026 (February has no 31st), then the next month mark is 31 March, and so on — each month step is measured from the original 31st. On 10 November 2026 that person is 36 years, 9 months and 10 days old. The same rule applies to the 30th in February and the 31st in April, June, September and November.

How do I find out how many days I have lived?

Enter your date of birth in the Exact age tab and the result shows your total days lived alongside the years, months and days — plus the same total in weeks, hours, minutes and seconds. The day count is the exact number of calendar days between the two dates, including every leap day in between. For example, someone born on 15 March 1991 has lived 13,024 days by 10 November 2026.

How do I find the day of the week I was born?

Enter your date of birth and the result line under your age tells you the weekday — for example, 15 March 1991 was a Friday and 1 January 2000 was a Saturday. The weekday comes from the Gregorian calendar, which is the calendar this calculator uses for every date.

How do I calculate the age difference between two people?

Use the Age gap tab: enter both dates of birth and the calculator shows the gap in whole years, months and days, plus the total days between the two birthdays. For example, someone born on 12 June 1988 is 7 years, 2 months and 22 days older than someone born on 3 September 1995 — a gap of 2,639 days. The order you enter the dates does not matter.

How do I find my age on a specific date in the past or future?

Use the Age on any date tab: enter your date of birth and the date you want to measure to — an application cutoff, a school enrolment date, a past anniversary, or a future date. The calculator returns your exact age on that date in years, months and days. The only rule is that the date you measure to cannot be before your date of birth.

Is my date of birth sent anywhere when I use this calculator?

No. The calculation runs entirely in your browser: your dates of birth are read by JavaScript on your own device and are never sent to any server. The only requests to other sites are the site's own analytics, which count page views. You can verify this with the privacy meter on the page, or by watching the Network tab in your browser's developer tools while you calculate.