Age Calculator

Find out exactly how old you are. Calculate your age in years, months, days, hours, and minutes from your date of birth. Our free age calculator uses the international age system and accounts for leap years, varying month lengths, and time zones. Over 8 billion people on Earth have unique ages—find yours instantly.

Key Takeaways

Your age is calculated from your date of birth to today (or any date you choose)
International age counts from 0 at birth, turning older on each birthday—used worldwide for legal purposes
Korean age counts as 1 at birth, adding 1 every January 1st (South Korea switched to international age in June 2023)
1 year = 365.25 days on average, accounting for leap years that occur every 4 years (with exceptions)
Chronological age (Y:M format) is used by psychologists and educators for developmental assessments
Life expectancy at birth is 73.4 years globally (WHO, 2024)

Date of Birth

Years Old

25 years, 3 months, 15 days

Total Months

—

Total Weeks

—

Total Days

—

Total Hours

—

🎉 Next Birthday In

— days

You'll be turning —

Zodiac Sign

—

Chinese Zodiac

—

Generation

—

Born On

—

Calculator Examples

See how our age calculator works with these real-world examples:

Scenario	Input	Result	Use Case
College freshman	Born: Sep 15, 2006	18 years, 5 months, 2 days	Age verification for enrollment
New parent	Born: Nov 23, 2024	0 years, 2 months, 25 days	Tracking baby milestones
Retirement planning	Born: Mar 8, 1960	64 years, 11 months, 9 days	Social Security eligibility
Driver's license	Born: Jun 30, 2009	15 years, 7 months, 18 days	Learner's permit eligibility
Leap year birthday	Born: Feb 29, 2000	25 years (exact on Feb 28/Mar 1)	Handling leap year births
Centennial milestone	Born: Jan 1, 1926	100 years, 1 month, 16 days	Planning a 100th birthday

More Age Calculators

Explore our specialized age calculators for different needs. Each calculator is designed for specific use cases, from passport applications to educational assessments:

How Age Is Calculated: Methods Worldwide

Age calculation varies across cultures and legal systems. While most of the world uses the international age system (counting from 0 at birth), several East Asian countries traditionally used different methods. Understanding these differences is important for international travel, legal documents, and cultural awareness.

International/Western Age System

The most common age-counting system worldwide. You start at age 0 at birth and turn 1 year old on your first birthday. Your age increases by exactly one year on each subsequent birthday. This system is used for all legal purposes in nearly every country, including identification documents, voting eligibility, and legal age thresholds.

The international age system is defined by ISO 8601, the international standard for date and time representation. When calculating exact age, we account for:

Varying month lengths: January has 31 days, February has 28 (or 29), April has 30, etc.
Leap years: Every 4 years (with exceptions for century years not divisible by 400)
Time zones: Your exact age depends on your local timezone at birth

Korean Age System (한국 나이)

Traditional Korean age counting considers you 1 year old at birth (counting time in the womb) and adds 1 year on every January 1st, regardless of your actual birthday. This means:

A baby born on December 31st is 1 year old at birth
The very next day (January 1st), that baby turns 2 in Korean age
Your Korean age is always 1-2 years higher than your international age

Important: South Korea officially adopted international age for all legal and administrative purposes in June 2023. However, Korean age is still commonly used in everyday conversation and cultural contexts. Learn more in our Korean Age Calculator guide.

Chinese Lunar Age (虚岁)

Similar to Korean age, the Chinese lunar age system (xū suì) counts 1 at birth. However, age increases at Chinese New Year (Lunar New Year) rather than January 1st. Since Chinese New Year falls between January 21 and February 20, the timing differs slightly from Korean age. This system is still used in traditional Chinese medicine, fortune telling, and the famous Chinese gender prediction chart.

Chronological Age (for Assessments)

Psychologists, educators, and healthcare professionals use chronological age expressed in a specific format: Years:Months (Y:M). For example, a child who is 7 years and 4 months old has a chronological age of 7:4. This precise measurement is essential for:

Pearson assessments (WISC, WPPSI, WAIS)
IQ and developmental testing
Special education evaluations
Pediatric growth chart comparisons (CDC Growth Charts)

Age Systems Comparison

This table shows how the same person would have different ages depending on which system is used:

Age System	Starting Age	When Age Increases	Where Used	Example (born July 15, 2000)
International	0 at birth	On each birthday	Worldwide (legal)	24 years old (in 2024)
Korean (traditional)	1 at birth	Every January 1st	South Korea (cultural)	26 years old (in 2024)
Chinese Lunar	1 at birth	Lunar New Year	China, Taiwan (cultural)	25-26 years old
Chronological (Y:M)	0:0 at birth	Monthly	Education, Psychology	24:5 (if May 2024)

Global Life Expectancy by Region

Life expectancy at birth varies significantly by region. According to World Health Organization (WHO) data, here's how average life expectancy compares across regions:

Japan

84.3 years

Western Europe

81.8 years

North America

78.4 years

Latin America

75.4 years

World Average

73.4 years

South Asia

70.2 years

Sub-Saharan Africa

61.2 years

Source: WHO Global Health Observatory, 2024 estimates. Use our Life Expectancy Calculator for country-specific data.

Age Milestones in Days

Many people celebrate milestone birthdays based on days lived rather than years. Here are the most popular day-based milestones, calculated using our Days Old Calculator:

Days	Equivalent Age	Milestone Significance	Notable Celebrations
1,000	2 years, 8 months, 26 days	First major milestone	"1000 days" baby celebrations in Japan
5,000	13 years, 8 months, 15 days	Teenager threshold	Popular among teens tracking their age
10,000	27 years, 4 months, 26 days	Most celebrated day milestone	10K day parties, social media celebrations
15,000	41 years, 1 month, 6 days	Mid-life milestone	Life reflection celebrations
20,000	54 years, 9 months, 17 days	20K club achievement	Pre-retirement milestone
25,000	68 years, 5 months, 28 days	Quarter of 100,000	Retirement era celebration
30,000	82 years, 2 months, 8 days	30K achievement	Longevity milestone
36,500	100 years	Century in days	Centenarian celebration

Learn more about day milestones in our Age in Days Calculator guide.

Fascinating Age Facts

Age and time present some surprising statistics and cultural quirks:

🎂

10,000 Days Old

You turn 10,000 days old at about 27 years and 5 months. This milestone has become increasingly popular to celebrate, especially among millennials.

💫

1 Billion Seconds

You turn 1 billion seconds old at exactly 31 years, 251 days, 13 hours, 34 minutes, and 54 seconds. That's roughly 31 years and 8 months.

🌍

World's Oldest Person

The verified oldest person ever was Jeanne Calment of France, who lived 122 years and 164 days (1875-1997).

📅

Leap Year Babies

Only about 5 million people worldwide were born on February 29. They experience their actual birthday only once every 4 years! Read our Leap Year Birthday guide.

👶

Most Common Birthday

September 9th is statistically the most common birthday in the US, followed by September 19th. The least common (excluding Feb 29) is December 25th.

🧓

Centenarians Rising

There are over 600,000 centenarians (people aged 100+) alive today. By 2050, this number is projected to reach 3.7 million.

Legal Age Thresholds by Country

Age determines eligibility for many activities worldwide. Here are common legal age thresholds in major countries, according to CIA World Factbook and national government sources:

Country	Voting Age	Driving Age	Drinking Age	Age of Majority
🇺🇸 United States	18	16 (varies by state)	21	18
🇬🇧 United Kingdom	18	17	18	18
🇨🇦 Canada	18	16	18-19	18-19
🇦🇺 Australia	18	17	18	18
🇩🇪 Germany	18	18 (17 with supervision)	16 (beer/wine), 18 (spirits)	18
🇯🇵 Japan	18	18	20	18
🇰🇷 South Korea	18	18	19	19
🇧🇷 Brazil	16 (optional), 18 (mandatory)	18	18	18

For comprehensive information, see our guides on Legal Ages by Country, Driving Ages, and Voting Ages.

World Population by Age Group

According to United Nations Population Division estimates for 2024:

0-14 years

25.4% (2.03 billion)

15-24 years

15.5% (1.24 billion)

25-54 years

40.5% (3.24 billion)

55-64 years

9.1% (728 million)

65+ years

9.5% (761 million)

Total world population: ~8.0 billion (2024). The 65+ population is the fastest-growing age group globally.

Generations by Birth Year

Knowing your birth year helps identify your generation. Generational definitions vary slightly by source, but here are the commonly accepted ranges according to Pew Research Center:

Generation	Birth Years	Age in 2024	Key Characteristics
Silent Generation	1928-1945	79-96	Great Depression, WWII childhood
Baby Boomers	1946-1964	60-78	Post-war boom, civil rights era
Generation X	1965-1980	44-59	Latchkey kids, MTV generation
Millennials (Gen Y)	1981-1996	28-43	Digital natives, 9/11, Great Recession
Generation Z	1997-2012	12-27	Smartphones, social media, COVID
Generation Alpha	2013-2025	0-11	AI, tablet natives, pandemic babies

Use our Generation Calculator to find your exact generation based on your birth year.

Frequently Asked Questions

Enter your date of birth in our calculator above. We calculate the exact years, months, and days between your birthdate and today's date. Our algorithm accounts for varying month lengths (28-31 days) and leap years (years divisible by 4, except century years not divisible by 400). The result shows your precise age in multiple units: years, months, weeks, days, hours, and minutes.

Korean age (한국 나이) is a traditional East Asian age system where you're counted as 1 year old at birth (valuing time in the womb) and everyone adds 1 year on January 1st, regardless of their actual birthday. This means a baby born on December 31st turns "2" the very next day! Your Korean age is typically 1-2 years higher than your international age. Important: South Korea officially adopted international age for all legal and administrative purposes in June 2023, though Korean age is still used culturally. Use our Korean Age Calculator to find yours.

Use our Days Old Calculator to find out exactly how many days you've been alive. Enter your birthdate and we'll calculate the total days, hours, minutes, and seconds since you were born. We also show when you'll reach milestone days like 10,000 days (about 27.4 years) or 20,000 days (about 54.8 years). Many people now celebrate these "day birthdays" as alternative milestones!

Chronological age is your exact age expressed in years and months, written as Y:M (e.g., 7:4 means 7 years and 4 months). It's the precise measurement used by psychologists, educators, and clinicians for developmental assessments. Common uses include Pearson assessments (WISC-V, WAIS-IV), IQ testing, reading level assessments, and special education evaluations. The chronological age must be calculated from the child's birthdate to the exact test date. Use our Chronological Age Calculator for accurate Y:M format results.

Our Life Expectancy Calculator uses WHO global health statistics for country-specific life expectancy averages. These are statistical averages for populations, not individual predictions. Actual lifespan varies significantly based on genetics, lifestyle (diet, exercise, smoking), healthcare access, socioeconomic factors, and environmental conditions. The calculator provides general perspective based on where you live and your gender, but should not be considered a medical prediction.

The "half your age plus 7" rule is a social guideline suggesting the youngest person you should date is half your age plus 7 years. For example, if you're 30, the minimum "acceptable" age would be (30÷2)+7 = 22. Conversely, the oldest you should date is calculated as (your age - 7) × 2 = 46. This rule appears to have originated in late 19th century France and became popular in English-speaking countries in the early 20th century. It's purely a social convention, not a scientific or legal rule. Use our Age Difference Calculator to explore age gaps.

10,000 days equals approximately 27 years, 4 months, and 26 days (accounting for leap years). This has become an increasingly popular milestone birthday, especially since social media made tracking such dates easier. Use our Days Old Calculator to find your exact 10,000-day birthday. Other popular day milestones include 5,000 days (13.7 years), 15,000 days (41.1 years), and 20,000 days (54.8 years). See our Age in Days guide for more information.

Yes! Leap years affect age calculations in several ways. When counting days lived, each leap year adds an extra day (February 29), making the average year 365.25 days. For people born on February 29 ("leaplings"), their actual birthday only occurs every 4 years—about 5 million people worldwide have this birthday. In non-leap years, leaplings typically celebrate on February 28 or March 1. Our calculator automatically handles all leap year scenarios correctly. Learn more in our Leap Year Birthday guide.

Chronological age is simply how many years you've been alive—the number our calculator shows. Biological age (also called physiological age) measures how old your body actually is based on various biomarkers. You can be chronologically 50 but biologically 40 (or 60) depending on factors like genetics, lifestyle, diet, exercise, and environmental exposure. Biological age is measured through tests examining DNA methylation, telomere length, and organ function. NIH research shows biological age is a better predictor of health outcomes than chronological age. Learn more in our Biological Age vs. Chronological Age guide.

Passport applications typically require your age on a specific date (either application date or travel date). Use our Age on Date Calculator to find your exact age on any date. Many countries have age-based rules: children under 16 often need shorter-validity passports, and applicants over 62 may be eligible for reduced fees. For US passports, the State Department has specific requirements based on age at time of application.

Zodiac Signs by Birth Date

Your birth date determines your Western zodiac sign. Here are all 12 signs with their date ranges:

Zodiac Sign	Symbol	Date Range	Element
Aries	♈	March 21 - April 19	Fire
Taurus	♉	April 20 - May 20	Earth
Gemini	♊	May 21 - June 20	Air
Cancer	♋	June 21 - July 22	Water
Leo	♌	July 23 - August 22	Fire
Virgo	♍	August 23 - September 22	Earth
Libra	♎	September 23 - October 22	Air
Scorpio	♏	October 23 - November 21	Water
Sagittarius	♐	November 22 - December 21	Fire
Capricorn	♑	December 22 - January 19	Earth
Aquarius	♒	January 20 - February 18	Air
Pisces	♓	February 19 - March 20	Water

Our calculator automatically shows your zodiac sign and Chinese zodiac animal based on your birthdate. Learn more in our Zodiac Sign Calculator guide.

Comprehensive Age Guides

Explore our in-depth guides on age calculation, life expectancy, legal ages, and more. Each guide includes data tables, charts, FAQs, and authoritative sources:

Guide • 550K monthly searches

Calculate Your Age Now

Enter your birthdate above to discover your exact age in years, months, days, hours, and minutes—plus your zodiac sign, generation, and next birthday countdown.

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