Age Calculator

A worked example

Take a birth date of June 15, 1990. On June 12, 2026, that's a chronological age of 35 years and a fraction. The calculator above breaks that down into the exact years, months, and days lived, plus totals: roughly 13,146 days, 1,878 weeks, and 315,513 hours alive. Most calculators stop at the years number; this one shows the rest because that's what people actually want for milestones and assessments.

Age in different formats — when each one matters

What people use age calculation for

The questions vary more than you'd expect. Parents check exact age in months for vaccine schedules and developmental screenings — pediatricians don't accept "two and a half," they want 30 months. Teachers and speech therapists need the years;months;days format for assessment scoring. People planning weddings or anniversaries want to know what age they'll be on a specific future date. Retirees check the day they hit Medicare or pension eligibility — usually 65 years from a birthday, but sometimes 65 plus a few months depending on the rule.

Adoptive parents and immigration applicants often need age at a specific past date, like the date a petition was filed. Athletes check eligibility for age-graded competitions. Insurance applications often pivot on whether you were 30 or 31 on the policy date. The chronological age calculator gives you the formatted output examiners reference; this one gives you everything.

Leap-year birthdays and other edge cases

If you were born on February 29, the calculator ages you against March 1 in non-leap years — the convention most US jurisdictions use for legal age. Some traditions count differently. East Asian age reckoning, for example, adds a year at birth and another at each lunar new year, which can make you up to two years older "on paper." This calculator uses the Western convention. For practical purposes — paperwork, school placement, age-restricted purchases — the number above is the one institutions will accept.