Age Calculator

How Old Am I? How to Calculate Your Age

Age calculation means expressing the time between your date of birth and today (or a specific date) in years, months and days. The tool above calculates your age instantly when you enter your birth date; it also shows how many days, weeks and hours you have lived and the time left until your next birthday.

The most common everyday uses of age calculation are: retirement applications, completing official documents, determining school enrollment age, health-screening age criteria and birthday countdowns.

The Age Calculation Formula

The basic age formula is: Age = Current Year − Birth Year. However this is only approximate. If your birthday has not occurred yet, your real age is one less. For an exact result, the month and day are also compared:

1. Calculate the year difference: Current year − Birth year
2. If the birth month and day have not occurred yet, subtract 1
3. Calculate the remaining month and day difference separately

This tool also accounts for leap years automatically. For people born on February 29, February 28 or March 1 is used in other years.

How Many Days Have I Lived?

The total day count covers all days since your date of birth, including leap years. The table below shows total days, weeks and hours for some age groups:

Calculating Age as of a Reference Date

The "Reference Date" field lets you calculate your age not as of today, but as of a specific date. This is useful in cases such as:

• Retirement planning: To answer "How old will I be in 2030?", set the reference date to 2030.
• Your age on a past date: To find your age when a specific event happened (graduation, marriage, starting a job).
• Children's school age: Enter a cut-off date such as September 1 to check a child's age at enrollment.

Birthday Countdown

After you calculate your age, the tool shows how many days are left until your next birthday. If today is your birthday, it displays "Today!". This is handy for planning celebrations or simply keeping track of the countdown. Knowing your exact age and the days remaining also helps with milestone planning — turning 18, 21, 30, 50 and other meaningful ages.

Why Exact Age Matters

Beyond curiosity, an exact age in years, months and days is needed for many practical purposes: medical assessments (where age in months matters for infants and children), legal thresholds, insurance and pension calculations, and eligibility for age-restricted services. Because manual calculation is error-prone — especially around leap years and month boundaries — this exact age calculator gives a reliable result every time. Enter your date of birth above to see your precise age and a full breakdown of the time you have lived.

Leap Years and February 29 Birthdays

Leap years add a day (February 29) every four years to keep the calendar aligned with Earth's orbit. A correct age calculator must count these extra days, and this tool does so automatically using the calendar date system. People born on February 29 — called "leaplings" — technically have a birthday only once every four years:

• In leap years their birthday falls on February 29 as normal.
• In common years it is usually observed on February 28 or March 1, depending on the country and purpose (legal vs. celebratory).

Whichever convention you follow, the total days-lived count stays accurate because every leap day since your birth is included.

Date of Birth Calculator and Birthday Calculator

This tool doubles as a date of birth calculator and a birthday calculator: from a single date of birth it derives your current age, the exact day of the week you were born, the total time you have lived and the days remaining to your next birthday. Common ways people use it include:

• Birthday planning: count down to the next celebration and find which weekday it lands on.
• Forms and applications: confirm an exact age for official documents, job or school applications.
• Milestones: work out the date you reach 18, 21, 65 or any other significant age.
• Comparing ages: use the reference-date field to compare ages between two people or two dates.

Quick Age Calculator vs Exact Age

If you only need a rough number, the quick age calculator approach is simply Current Year − Birth Year. But this can be off by a year if the birthday has not happened yet. To calculate my age precisely, the day and month must also be compared — which is exactly what this tool does. The table below shows the difference for someone born on 15 December 1990, evaluated on 9 June 2026:

For everyday questions like "how old am I?" the exact method is always the safer choice, and this free age calculator handles every detail — leap years, month lengths and birthdays — for you.