alderskalkulator – Hvor gammal är jag?
Calculate your exact age in years, months, days, hours, and minutes. Find out how many days you've been alive.
Slik bruker du denne kalkulatoren
- Skriv inn Date of Birth
- Klikk på Beregn-knappen
- Les resultatet som vises under kalkulatoren
How Age Is Calculated
Age calculation sounds simple but involves several nuances. The basic approach is to subtract the birth date from today's date, counting completed years, months, and days:
- Subtract the birth year from the current year to get a base number
- If today's month/day is before the birth month/day, subtract 1 (birthday hasn't occurred yet this year)
- Calculate remaining months and days to get the precise result
Example: Born on August 15, 1990, today is March 11, 2026. The base difference is 35 years. Since March 11 is before August 15, subtract 1: 35 years, then count from Aug 15 to Mar 11 = 6 months and 25 days. Result: 35 years, 6 months, 25 days.
The calculation must account for leap years (February has 29 days instead of 28) and varying month lengths (28–31 days). People born on February 29 typically celebrate their birthday on February 28 or March 1 in non-leap years.
Age Milestones Across Cultures and Law
The legal and cultural significance of specific ages varies dramatically around the world:
| Age | Common Milestone | Notes |
|---|---|---|
| 1 | First birthday | Major celebration in Korean (dol), Chinese, and many Asian traditions |
| 13 | Bar/Bat Mitzvah | Jewish coming-of-age ceremony; also US "teenager" status |
| 15 | Quinceañera | Latin American tradition marking womanhood |
| 16 | Driving age (US) | Varies: 17 in UK, 18 in most of Europe |
| 18 | Voting age (most countries) | Legal adulthood in most of the world |
| 21 | Full legal adulthood (US) | Drinking age in USA; already adult in most other countries at 18 |
| 60–65 | Retirement age | Varies by country; trend toward 67+ in Western nations |
| 100 | Centenarian | UK monarch sends a congratulatory letter |
Chronological Age vs Biological Age
Your chronological age is simply how many years, months, and days have passed since your birth — what our calculator computes. Your biological age (sometimes called "physiological age") reflects how old your body actually is based on health markers, and can be significantly different from your chronological age.
Biological age is estimated through markers such as:
- Telomere length: The protective caps on chromosomes shorten with each cell division. Shorter telomeres correlate with accelerated aging.
- DNA methylation (epigenetic clocks): The Horvath clock and similar models can estimate biological age within a few years using blood or saliva samples.
- VO2 max: Aerobic capacity declines with age; a high VO2 max for your age group indicates younger biological age.
- Grip strength, bone density, inflammatory markers (CRP), and resting heart rate are also used.
Lifestyle choices have a measurable impact: regular exercise, quality sleep, not smoking, and a Mediterranean-style diet have all been shown to reduce biological age by 5–10 years relative to chronological age.
Dog Years and Animal Age Equivalents
The popular "1 human year = 7 dog years" formula is a myth — dogs age much faster in early life and slower later. A 2020 study in Cell Systems proposed a new formula based on DNA methylation: Dog age = 16 × ln(human age) + 31.
| Dog Age | Approximate Human Equivalent |
|---|---|
| 1 year | ~31 years |
| 2 years | ~42 years |
| 5 years | ~57 years |
| 10 years | ~68 years |
| 15 years | ~74 years |
Other animal comparisons: cats age roughly 15 human years in their first year, then 9 in year 2, then 4 per year thereafter. Horses: multiply by 3 for the first 3 years, then 2.5 per year after.
Age Calculation in Different Calendar Systems
Not all age calculations use the Gregorian calendar. Different cultures and legal systems define age differently:
- East Asian age reckoning: In traditional Korean, Chinese, and Japanese systems, a person is considered 1 year old at birth (the gestation period counts as a year). Korea officially abolished this system in 2023, switching to international (Gregorian) age.
- Islamic (Hijri) calendar: Based on lunar cycles (~354 days/year), so an Islamic year is about 11 days shorter than a Gregorian year. A person who is 30 in Gregorian years is approximately 30.9 in Hijri years.
- Ethiopian calendar: Has 13 months and runs about 7–8 years behind the Gregorian calendar, which sometimes causes confusion for Ethiopians who appear to be younger by international standards.
For legal purposes (passports, contracts, retirement eligibility), always use Gregorian chronological age unless specifically stated otherwise.
Why Knowing Your Exact Age Matters
Precise age calculation matters in more situations than most people realize:
- Legal documents: Passport applications, visa forms, and official records require exact date of birth, and some systems verify age to the day.
- Medical dosing: Many pediatric drug doses are calculated by age in months, not years. A 23-month-old and a 25-month-old may receive different doses.
- Sports eligibility: Junior and age-group categories in athletics, swimming, and triathlon use exact age on the first day of competition or as of December 31 of the competition year.
- Insurance premiums: Life insurance rates often jump at age milestones (50, 55, 60). Knowing your exact months remaining can inform the timing of policy purchases.
- Social Security / pension eligibility: In the US, early Social Security benefits begin at exactly age 62, and full retirement age ranges from 66 to 67 depending on birth year.
💡 Visste du?
- The oldest verified person ever was Jeanne Calment of France, who lived to 122 years and 164 days (1875–1997).
- In South Korea, people are traditionally considered 1 year old at birth (everyone gains a year on Lunar New Year) — though South Korea officially adopted the international age system in 2023.
- Scientists estimate the theoretical maximum human lifespan is around 120–150 years based on cellular aging and DNA repair mechanisms.
Sist oppdatert: March 2026
Frequently Asked Questions
How is age calculated exactly?
Age is calculated by finding the difference between your birth date and today, counting completed years, then remaining months and days. The calculation accounts for leap years and varying month lengths. A person born August 15, 1990 turns 35 on August 15, 2025 — not before.
At what age am I considered a senior?
This varies by context. In most Western countries, 65 is the traditional retirement/senior age, often qualifying for Medicare (US) or state pension (UK). Many organizations define senior discounts starting at 55 or 60. Medically, 'geriatric' typically refers to patients 65+.
How do I calculate age in months?
Count the total complete months from your birth date to today: (years × 12) + remaining months. For example, someone who is 2 years and 5 months old is 29 months old. Our calculator computes this automatically.
What is my age in days?
Multiply your age in years by 365.25 (accounting for leap years) and add the days since your last birthday. A 30-year-old has lived approximately 10,957 days. Our calculator provides this precise count.
What if I was born on February 29 (leap day)?
People born on February 29 have a birthday only every 4 years. In non-leap years, most countries legally recognize their birthday as either February 28 or March 1 for age-related purposes (like reaching voting age or driving age). The US and UK generally use March 1.
How does the Korean age system differ from international age?
In traditional Korean age reckoning, everyone is 1 year old at birth (the year in the womb counts), and everyone gains a year on January 1st regardless of their birthday. A Korean baby born in December would be considered 2 years old by January 1st of the following year. South Korea officially switched to international age calculation in June 2023.
What is the difference between chronological age and biological age?
Chronological age is how many years have passed since birth. Biological age reflects how old your body is based on physical health markers like telomere length, VO2 max, and DNA methylation patterns. Healthy lifestyle choices (exercise, sleep, diet, no smoking) can make your biological age significantly younger than your chronological age.
At what age are you considered middle-aged?
There is no universal definition, but middle age is generally considered 40–60 years old in Western cultures. The WHO defines middle age as 45–59. Some researchers define it relative to life expectancy — roughly the middle third of your expected lifespan.