Free Age Calculator

Exact age is calculated from the date of birth to today, counting complete years, remaining months, and residual days. Leap years and varying month lengths (28, 29, 30, or 31 days) are all accounted for. This calculator performs the precise calculation automatically.

The birth date is subtracted from the current date. If the current day is less than the birth day, a month is “borrowed.” If the current month is less, a year is borrowed. The result is the exact age in years, months, and days.

A common year has 365 days, while a leap year has 366. A year is a leap year if divisible by 4 but not by 100, unless also divisible by 400. For example, 2000 and 2024 are leap years; 1900 is not.

The zodiac sign is based on birth month and day. Each sign covers about 30 days: Aries (Mar 21-Apr 19), Taurus (Apr 20-May 20), Gemini (May 21-Jun 20), Cancer (Jun 21-Jul 22), Leo (Jul 23-Aug 22), Virgo (Aug 23-Sep 22), Libra (Sep 23-Oct 22), Scorpio (Oct 23-Nov 21), Sagittarius (Nov 22-Dec 21), Capricorn (Dec 22-Jan 19), Aquarius (Jan 20-Feb 18), Pisces (Feb 19-Mar 20).

Generations are demographic groups defined by birth year: Silent Generation (1928-1945), Baby Boomer (1946-1964), Generation X (1965-1980), Millennial (1981-1996), Generation Z (1997-2012), Generation Alpha (2013-present). Each shares common cultural and social experiences.

Decimal age expresses your age as a single number with decimals (e.g. 34.72 years) instead of years-months-days. It's used in medical settings (pediatric growth charts, clinical trials), insurance (premium calculations), legal documents, and official forms requiring a precise numeric value. It's calculated by dividing total days lived by 365.25 (average year length including leap years).

One billion seconds equals approximately 31 years and 8 months. If you were born in 1990, you hit your billionth second around 2021. It's a popular milestone to celebrate: our calculator shows the exact date when you reached (or will reach) this and other life milestones.

Each planet orbits the Sun at a different speed: Mercury in 88 days, Venus in 225, Mars in 687, Jupiter in 4,333, Saturn in 10,759. Your Earth age in days is divided by the planet's orbital period. A 30-year-old on Mars would be about 16 Martian years old, while on Mercury they'd be over 124!