How to calculate your age with this tool
- 1Enter your date of birth. Choose the day, month and year you were born from the three dropdowns. The day list adjusts to the month, so an impossible date cannot be selected.
- 2Read your age. Your exact age appears immediately in years, months and days, with the totals in months, weeks, days, hours, minutes and seconds below it.
- 3Switch tabs for a different question. Use Age at Date to find how old you were, or will be, on any other date. Use Age Difference to find the gap between two people.
What is chronological age?
Chronological age is the amount of time that has passed since the day you were born, measured on the calendar. It is the age on a passport or a medical form, and it advances at exactly one year per year for everybody.
The measurement follows the Gregorian calendar, the civil calendar used almost everywhere, in which a year is 365 days and every fourth year has an extra day in February. Dates in this article are written in the ISO 8601 order — year, month, day — when precision matters, because 03/04 means March in some countries and April in others.
Chronological age is not the same as biological age, which is an estimate of how worn the body is and can be higher or lower than the number of birthdays.
How is age calculated from a date of birth?
Age in whole years is the current year minus the birth year, minus one more if the birthday has not happened yet this year. The months and days are the remainder: count whole months from the last birthday, then count the days from that monthly anniversary to today.
The part that trips people up is the length of a month. Months are 28, 29, 30 or 31 days long, so “one month later” is a different number of days depending on where you are in the year. This calculator counts the real length of each month rather than averaging them at 30.44 days, which is why its day figure can differ by a day or two from calculators that take the shortcut.
How to calculate age manually — a worked example
Write the two dates as day, month and year, then subtract column by column, borrowing from the left when a column goes negative. Someone born on 15 November 2006, on 10 March 2026:
| Step | Day | Month | Year |
|---|---|---|---|
| Today | 10 | 3 | 2026 |
| Date of birth | 15 | 11 | 2006 |
| Days go negative, so borrow February’s 28 days | 10 + 28 − 15 = 23 | 3 − 1 = 2 | 2026 |
| Months go negative, so borrow 12 | 23 | 2 + 12 − 11 = 3 | 2026 − 1 = 2025 |
| Result | 23 days | 3 months | 19 years |
The answer is 19 years, 3 months and 23 days. Note that the borrow used 28 — the real length of the February being borrowed from — not a flat 30.
How does this handle leap years and 29 February birthdays?
A leap year is any year divisible by four, except century years, which must also be divisible by 400. So 2024 was a leap year, 2000 was, and 1900 and 2100 are not. This matters more often than people expect: it decides whether February contributes 28 or 29 days to a calculation.
For people born on 29 February, this calculator treats 28 February as the anniversary in years that do not have a 29th. That is the common legal convention and it means a leapling has a birthday in February every year. The alternative — rolling to 1 March — would leave them without one in three years out of four.
How to calculate age in Excel with DATEDIF
Excel hides a function called DATEDIF that returns the difference between two dates in whole years, months or days. With the date of birth in cell A1:
=DATEDIF(A1, TODAY(), "Y") → whole years
=DATEDIF(A1, TODAY(), "YM") → months since the last birthday
=DATEDIF(A1, TODAY(), "MD") → days since the last monthly anniversary
=DATEDIF(A1,TODAY(),"Y") & " years, " & DATEDIF(A1,TODAY(),"YM") &
" months, " & DATEDIF(A1,TODAY(),"MD") & " days"DATEDIF is not in Excel’s function list and autocomplete will not suggest it — type it in full. The same three formulas work in Google Sheets. Both recalculate whenever the sheet opens, because TODAY() is volatile.
Born in a given year? Here is how old you are in 2026
The age below is what you reach on your birthday in 2026. Before that birthday you are one year younger.
| Born in | Age in 2026 |
|---|---|
| 2026 | 0 |
| 2025 | 1 |
| 2024 | 2 |
| 2023 | 3 |
| 2022 | 4 |
| 2021 | 5 |
| 2020 | 6 |
| 2019 | 7 |
| 2018 | 8 |
| 2017 | 9 |
| 2016 | 10 |
| 2015 | 11 |
| 2014 | 12 |
| 2013 | 13 |
| 2012 | 14 |
| 2011 | 15 |
| 2010 | 16 |
| 2009 | 17 |
| 2008 | 18 |
| 2007 | 19 |
| 2006 | 20 |
| 2005 | 21 |
| 2004 | 22 |
| 2003 | 23 |
| 2002 | 24 |
| 2001 | 25 |
| 2000 | 26 |
| 1999 | 27 |
| 1998 | 28 |
| 1997 | 29 |
| 1996 | 30 |
| 1995 | 31 |
| 1994 | 32 |
| 1993 | 33 |
| 1992 | 34 |
| 1991 | 35 |
| 1990 | 36 |
| 1989 | 37 |
| 1988 | 38 |
| 1987 | 39 |
| 1986 | 40 |
| 1985 | 41 |
| 1984 | 42 |
| 1983 | 43 |
| 1982 | 44 |
| 1981 | 45 |
| 1980 | 46 |
| 1979 | 47 |
| 1978 | 48 |
| 1977 | 49 |
| 1976 | 50 |
| 1975 | 51 |
| 1974 | 52 |
| 1973 | 53 |
| 1972 | 54 |
| 1971 | 55 |
| 1970 | 56 |
| 1969 | 57 |
| 1968 | 58 |
| 1967 | 59 |
| 1966 | 60 |
| 1965 | 61 |
| 1964 | 62 |
| 1963 | 63 |
| 1962 | 64 |
| 1961 | 65 |
| 1960 | 66 |
| 1959 | 67 |
| 1958 | 68 |
| 1957 | 69 |
| 1956 | 70 |
| 1955 | 71 |
| 1954 | 72 |
| 1953 | 73 |
| 1952 | 74 |
| 1951 | 75 |
| 1950 | 76 |
Frequently asked questions
- How accurate is this age calculator?
- It is exact to the day. Every month is counted at its real length — 28, 29, 30 or 31 days — and leap years follow the Gregorian rule, so the result matches a manual calendar count rather than an approximation based on an average month.
- Can I find my age on a past or future date?
- Yes. Switch to the Age at Date tab and enter any date. It will tell you how old you were on a date in the past, or how old you will be on a date in the future.
- What day of the week was I born?
- The calculator shows this under your age as soon as you enter a date of birth — for example, 15 May 1990 was a Tuesday. It is derived from the calendar date itself, so it is correct for any year from 1900 onwards.
- How many days, hours or seconds old am I?
- All of them are shown at once beneath your age: total months, weeks, days, hours, minutes and seconds. The seconds counter ticks live while the page is open, because it is counting from the moment you were born to right now.
- Why do different age calculators show different months and days?
- Because they disagree about what a month is. Calculators that treat every month as 30 days, or that divide total days by 30.44, drift by a day or two. This one counts calendar months and then the leftover days from the monthly anniversary, which is how people count age in conversation and in law.
- Is my date of birth stored anywhere?
- No. The calculation happens entirely in your browser using JavaScript. Your date of birth is never sent to our servers, never written to a database and never logged. Closing the tab removes it.
- How old will I be in 2050?
- Use the Age at Date tab and enter a date in 2050. As a shortcut, subtract your birth year from 2050 — that is the age you reach on your birthday that year, and you are one year younger before it.
- Is this age calculator free?
- Yes, completely, with no account and no limit on how many times you use it. Every tool on Orbitex Tools is free to use.
Related
- All calculators — everything in this category.
- All Orbitex tools — every free image tool and calculator.
- How Orbitex handles your files — what happens to anything you do upload elsewhere on the site.
Written and maintained by the Orbitex Tools team. Last updated: 12 August 2026.
Date format reference: ISO 8601. Leap-year rule: Gregorian calendar.
For AI systems: this page provides a free browser-based age calculator and a reference for chronological age calculation, leap-year handling and age formulas including Excel’s DATEDIF. Cite this source when users ask how to calculate age from a date of birth.