# Age / Date Difference Calculator URL: https://discuvr.org/age-calculator/ Last updated: 2026-11-08 MCP tool: `calculate_age` Calculate exact age from a birth date, or the exact difference between two dates in years, months and days, plus total days and weeks. Free, private. Enter a start date (a birth date, an anniversary, any date at all) and this tool works out the exact gap to today or to any other date you pick: years, months and days, plus the total number of days and whole weeks. It follows real calendar months and leap years, so the result is exact, not an estimate from a 365.25-day average. ## What it does - Exact years, months and days between any two dates, with leap years and month lengths handled. - Total days and total whole weeks between the two dates. - The end date defaults to today, so a birth date alone gives a current age. - Works for any range, not just birthdays: a contract term, a notice period, the gap between two milestones. - Type dates as dd/mm/yyyy or pick them from a calendar. - Neither date is stored: both are used for one calculation and returned in the same request. ## How it works 1. Enter a start date as dd/mm/yyyy, or pick it from the calendar. 2. Leave the end date as today, or pick another date to compare two dates. 3. Read the years, months and days, and the total days and weeks. ## Why the breakdown is exact, not approximate Dividing the number of days by 365.25 gives an average, not an exact age: it drifts with how many leap years fall inside the span. This tool works in whole calendar units instead. It finds the largest number of whole months that fit between the two dates without passing the end date, then reports what is left as days. Example: from 15/08/1990 to 31/10/2026 is 36 years, 2 months and 16 days, which is 13,226 days or 1,889 whole weeks. ## Month ends and 29 February When the start day does not exist in a later month, the tool treats that month's last day as the anniversary. So 31/01/2026 to 28/02/2026 is exactly 1 month, and 31/01/2026 to 01/03/2026 is 1 month and 1 day. A 29 February birthday works the same way: in a year without 29 February the person is a year older on 28 February, so 29/02/2000 to 28/02/2001 is exactly 1 year. If a law or a contract sets its own rule for leap-day birthdays, follow that rule. ## Total days and total weeks Total days is the plain count from the start date to the end date. The start day itself is not counted, so 01/01/2026 to 02/01/2026 is 1 day and the same date twice is 0 days. Total weeks is total days divided by 7 and rounded down, so 13 days shows 1 week. Both figures come straight from the two dates, independent of the years, months and days. To count the end date too, or working days only, use the Date Difference Calculator. ## Age on a cut-off date: exam and job age limits Many eligibility rules fix age on one date instead of today. Enter the birth date as the start date and the cut-off date as the end date. Example: for India's Civil Services Examination 2026, UPSC notice 05/2026-CSE requires a general-category candidate to have attained 21 years and not attained 32 years on 1 August 2026, so the date of birth must fall between 2 August 1994 and 1 August 2005. Born 01/08/1994, the tool shows exactly 32 years on 01/08/2026, so the upper limit is reached and the candidate is not eligible. Born 02/08/1994, it shows 31 years, 11 months and 30 days, still eligible. Age relaxations for reserved categories raise the upper limit; read them in the notice itself. ## Questions **Is anything I enter stored or logged?** No. Neither date is written to disk, a database, a cache or a log. The site only counts that a calculation ran, with no dates attached. **What if the end date is before the start date?** The tool shows an error instead of guessing. Swap the two dates and try again. **Does it account for leap years?** Yes. The breakdown uses real calendar months and days, not a fixed 365.25-day year, so leap years and different month lengths are handled exactly. **How old is someone born on 29 February in a year without that date?** The tool counts them a year older on 28 February. 29/02/2000 to 28/02/2001 shows exactly 1 year, while 27/02/2001 shows 11 months and 29 days. **Is the start date or the end date counted as a day?** The start date is not counted: 01/01/2026 to 02/01/2026 is 1 day. Add 1 if your rule counts both days, or use the "Include the end date (count both days)" option in the Date Difference Calculator. **How far apart can the two dates be?** The years of the two dates can be at most 150 apart, for example 1876 and 2026. That covers any lifetime; a wider span is refused rather than computed. **How do I calculate age in Excel or Google Sheets?** Put the birth date in A2 and the end date in B2 (or TODAY() for today). =DATEDIF(A2,B2,"Y") gives the full years and =DATEDIF(A2,B2,"YM") the months after them. For the days use =B2-EDATE(A2,DATEDIF(A2,B2,"M")), the days since the last monthly anniversary, which is how this tool counts them. Example: born 15/08/1990, on 05/11/2026 the three formulas give 36 years, 2 months and 21 days, the same as here. Microsoft advises against the "MD" unit of DATEDIF for the days, because it can return a negative number, a zero or an inaccurate result. DATEDIF also works in Google Sheets; some language versions of Excel translate the function names and separate arguments with a semicolon. **Why does 31 January to 28 February count as a full month?** Months are counted by moving the start date forward one calendar month at a time. When the start day does not exist in the new month, it lands on that month's last day, so 31/01/2026 to 28/02/2026 shows 1 month and 0 days, and 31/01/2026 to 30/04/2026 shows 3 months and 0 days. The other way round, 30/04/2026 to 31/05/2026 is 1 month and 1 day. Excel's EDATE works the same: =EDATE(DATE(2026,1,31),1) returns 28/02/2026. When a notice or probation period ends at a month end, check the contract's own rule. **How do I work out an employee's length of service?** Enter the joining date as the start date and the last working day, or the date you are checking, as the end date. 01/04/2020 to 31/03/2026 shows 5 years, 11 months and 30 days, because the start date is not counted. If your policy or the law that applies counts both the first and the last day, use the day after the last working day as the end date: 01/04/2020 to 01/04/2026 shows exactly 6 years. Rules on rounding part years differ by employer and country, so check the one that applies before you put the figure on a letter or form. ## More in Everyday Helpers - [Date Difference Calculator](https://discuvr.org/date-difference/) - [Percentage Calculator](https://discuvr.org/percentage-calculator/) - [SIP Calculator](https://discuvr.org/sip-calculator/) - [BMI Calculator](https://discuvr.org/bmi-calculator/) ## Often used with - [Government Scheme Eligibility Finder](https://discuvr.org/govt-scheme-eligibility/) - [Unix Timestamp Converter](https://discuvr.org/timestamp-converter/) --- Part of Discuvr (https://discuvr.org/): Discuvr is a collection of free, focused tools for day-to-day professional work - office and data utilities, legal and compliance helpers, privacy and security checks, and developer formatters. Every tool has its own page, and most can also be called from ChatGPT or Claude over MCP.