DigiKitAdvanced Age Calculator - DigiKitApp
Calculate age in years and months between two dates.
When should you use this?
Use this when you need the duration between two dates in years and months, for clarifying a contract term or calculating an age precisely.
When shouldn't you use this?
If a rough year difference is all you need ("about 5 years"), this tool gives more detail than necessary; simple subtraction might be enough for a quick estimate.
Step-by-step
- Enter the person's date of birth in the Birth date field. If a date picker opens, you can pick the day, month and year from it.
- If you need the age on a specific day rather than today, fill in the As of date (optional) field. A deadline for an application or the end date of a contract are typical choices.
- Click Run. The result shows up below the form in years and months.
- To try another date, change only the field you need and click Run again.
Example
Say a scholarship requires applicants to be under 25 on September 1, 2026. You were born on March 15, 2001. Enter that as the birth date and September 1, 2026 as the as of date, and the calculator returns 25 years and 5 months. So by the cutoff you have already turned 25 and don't qualify. If you had left the second field empty, the tool would have measured your age as of today, which answers a different question. Whenever an age limit is tied to a specific day, fill in that date.
How are years and months worked out?
The tool gives the difference between two dates in years and months; it does not show days. The calculation goes like this: take the difference in years, then the difference in months; if the day of the as-of date is smaller than the birth day, one month is subtracted, and if the months go negative, one year is subtracted. Example: for someone born on 20 May 1990, the result as of 17 October 2026 is 36 years 4 months. For someone born on 29 February 2000, 28 February 2026 gives 25 years 11 months and 1 March 2026 gives 26 years 0 months; in other words, in non-leap years the birthday counts as reached on 1 March.
Things to watch
- If you leave the as-of date empty, today's date is used.
- If the birth date is after the as-of date the tool shows no warning, only a negative value: someone born on 1 January 2030 shows -4 years 9 months as of 17 October 2026.
- If you need a number of days, use the date difference calculator.
- For official purposes age is worked out under the organization's own rule; treat the result as a pre-check.
Things to keep in mind
- An as of date earlier than the birth date gives a meaningless result. Double-check the year in particular, since one wrong digit can shift the answer by a decade.
- For people born on February 29, organizations don't all agree on whether the birthday falls on February 28 or March 1 in non-leap years. For anything official, go with the organization's own rule.
- Months have different lengths. If you need the exact number of days between two dates, multiplying the months by 30 won't give you the right figure.
- Schools, pension schemes and government offices calculate age using their own rules. Treat this result as a quick check before you apply, not as the final word.
Frequently asked questions
How accurate are the results?
Calculations use standard mathematical formulas; for official purposes (tax, loan applications, etc.) we recommend confirming current rates with the relevant institution.
Are the numbers I enter saved?
No, no numbers are sent to a server; the calculation happens entirely in your browser.
Can I use this on mobile?
Yes, the tool works smoothly on all screen sizes.