How to Calculate Your Exact Age — Years, Months, Days & More

Step-by-step: age in years

To calculate age in complete years:

Subtract your birth year from the current year: 2026 − birth year = approximate age
If your birthday has NOT yet occurred this year, subtract 1
If your birthday HAS occurred this year (or is today), keep the result

Example 1: Born September 15, 1990 — today is April 10, 2026
2026 − 1990 = 36. Birthday (September 15) has not occurred yet in 2026. Age = 35 years.

Example 2: Born March 5, 1990 — today is April 10, 2026
2026 − 1990 = 36. Birthday (March 5) has already occurred in 2026. Age = 36 years.

Step-by-step: age in years, months, and days

For a precise age including months and days:

Start with your complete years (see above)
Count complete months since your last birthday
Count remaining days since the last complete month

Example: Born June 20, 1988 — today is April 10, 2026

Complete years: 2025 − 1988 = 37 (birthday June 20 has not passed yet in 2026)
Months since June 20, 2025: July, August, September, October, November, December, January, February, March = 9 complete months
Days since March 20: March 20 → April 10 = 21 days
Result: 37 years, 9 months, 21 days

Age in other units

Unit	Formula	Example (born Jan 1, 1990 → today Apr 10, 2026)
Years	Current year − birth year (adjusted)	36 years
Months	Years × 12 + extra months	~435 months
Weeks	Total days ÷ 7	~1,895 weeks
Days	Count all days from birth to today	~13,249 days
Hours	Days × 24	~317,976 hours

How to calculate age for someone born in a specific year

Birth Year	Age in 2026 (before birthday)	Age in 2026 (after birthday)
1950	75	76
1960	65	66
1970	55	56
1980	45	46
1990	35	36
2000	25	26
2010	15	16
2020	5	6

Age calculation edge cases

Leap day birthdays (February 29): People born on February 29 are often considered to officially turn a year older on February 28 in non-leap years, or March 1 — depending on local laws and conventions.

Age in different countries: Most countries count age from birth (Western convention). South Korea traditionally counted age differently — a baby was born "1 year old" and everyone gained a year on January 1 — but South Korea officially moved to the international convention in 2023.

FAQ

How old am I if I was born in 1990?

If you were born in 1990, you are 35 or 36 years old in 2026, depending on whether your birthday has passed. Before your birthday: 35. On or after your birthday: 36.

How old am I if I was born in 2000?

If you were born in 2000, you are 25 or 26 years old in 2026, depending on whether your birthday has passed this year.

How old am I if I was born in 1980?

If you were born in 1980, you are 45 or 46 years old in 2026, depending on whether your birthday has passed this year.

How do I calculate my age in days?

To calculate your age in days, multiply your age in years by 365.25 (to account for leap years). For an exact count, use a date calculator that counts every individual day from your birth date to today.

What is chronological age?

Chronological age is the actual amount of time that has passed since birth, measured in years (and sometimes months and days). It differs from "biological age," which refers to how old your body appears physiologically.

How do I calculate the age of someone who has died?

Subtract the birth year from the year of death, then adjust if the birthday had not yet occurred in the year of death. For example, born March 10, 1920 — died January 5, 1995: 1995 − 1920 = 75, minus 1 because January 5 is before March 10 = age 74 at death.

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