How the age calculator works

This calculator reports age as completed calendar years, then remaining calendar months, then remaining calendar days between the date of birth and the target date. It does not divide the total number of elapsed days by an average year length (365 or 365.25), because calendar months and years vary in length. The total number of elapsed days is also shown separately, and the whole calculation runs instantly in your browser.

Age today or on a specific date

Leave “Calculate age” on Today to use the current calendar date on your device, or choose “On a specific date” to enter the exact date to calculate age on. The tool does not use your location, time zone conversions, or a network clock — it simply reads today’s calendar date on your device for Today mode.

How February 29 birthdays are handled

For this calendar calculation, PocketSpry treats February 28 as the anniversary date in non-leap years. So a person born on February 29, 2000 completes another year on February 28 in a non-leap year. This is a calculation convention, not a legal-age rule — the legal treatment of leap-day birthdays can vary by jurisdiction and context.

Frequently asked questions

How is age calculated?: Using completed calendar years, months, and days between the birth date and the target date.
Does this calculator use 365 days per year?: No. Calendar years and months vary in length, so the age breakdown uses calendar boundaries rather than dividing elapsed days by 365 or 365.25. The total elapsed days are shown separately.
How are February 29 birthdays handled?: PocketSpry uses February 28 as the anniversary date in non-leap years for this calendar calculation. This is a calculator convention, not a legal-age rule.
Can I calculate someone’s age on a past date?: Yes, as long as the selected target date is on or after the birth date.
Does this determine legal age?: No. It calculates calendar age only and does not determine legal eligibility or age requirements.