Birth Year Calculator
Calculate birth year from age or find age from birth year. Get your generation, Chinese zodiac sign, and more!
Calculate Birth Year
The date for which you want to calculate
This affects the calculation by ±1 year
Results
Enter Age
Enter an age to calculate the birth year
Quick Age to Birth Year Reference
| Age | Birth Year | Generation | Chinese Zodiac |
|---|---|---|---|
| 5 years | 2021 | Generation Alpha | 🐂 Ox |
| 10 years | 2016 | Generation Alpha | 🐵 Monkey |
| 15 years | 2011 | Generation Z | 🐇 Rabbit |
| 18 years | 2008 | Generation Z | 🐀 Rat |
| 21 years | 2005 | Generation Z | 🐓 Rooster |
| 25 years | 2001 | Generation Z | 🐍 Snake |
| 30 years | 1996 | Millennials / Gen Y | 🐀 Rat |
| 35 years | 1991 | Millennials / Gen Y | 🐐 Goat |
| 40 years | 1986 | Millennials / Gen Y | 🐅 Tiger |
| 45 years | 1981 | Millennials / Gen Y | 🐓 Rooster |
| 50 years | 1976 | Generation X | 🐉 Dragon |
| 60 years | 1966 | Generation X | 🐴 Horse |
| 70 years | 1956 | Baby Boomers | 🐵 Monkey |
| 80 years | 1946 | Baby Boomers | 🐕 Dog |
* Based on current year (2026) assuming birthday has passed
How to Calculate Birth Year
The Birth Year Formula
Calculating birth year from age is straightforward, but requires consideration of whether the birthday has occurred:
Birth Year = Current Year - Age
Important adjustment: If the birthday hasn't occurred yet this year, subtract an additional year from the result.
Why Birthday Timing Matters
The "before or after birthday" option is crucial because:
After Birthday
If someone's birthday has already passed this year, they've already "turned" their current age, so we use the simple formula.
Before Birthday
If the birthday is still coming, they were born one year earlier than the simple calculation suggests, so we subtract an additional year.
Example Calculations
Example 1: Birthday has passed
Someone is 30 years old in 2026 and their birthday was in March (it's now November).
2026 - 30 = 1994
Birth Year: 1994
Example 2: Birthday hasn't passed
Someone is 30 years old in 2026 and their birthday is in December (it's now November).
2026 - 30 - 1 = 1993
Birth Year: 1993
Generation Guide
Generation Alpha
Digital natives, AI era
Generation Z
Social media, smartphones
Millennials (Gen Y)
Internet, digital pioneers
Generation X
Latchkey kids, MTV generation
Baby Boomers
Post-war prosperity
Silent Generation
Great Depression, WWII
Frequently Asked Questions
How do I calculate birth year from age?
Subtract the age from the current year. If the birthday hasn't occurred yet this year, subtract an additional year. For example: In 2026, a 25-year-old (birthday passed) was born in 1999.
What year was I born if I am 30?
If you're 30 in 2026 and your birthday has passed, you were born in 1994. If your birthday hasn't occurred yet, you were born in 1993.
Why is the birthday timing important?
Because your age increases by one on your birthday each year. Before your birthday, you're technically still the age you were last year, which means you were born one year earlier.
How can I find someone's birth year if I only know their age?
Use our calculator or the formula: Current Year - Age = Birth Year. Remember to subtract 1 more year if their birthday hasn't happened yet this year.
What generation am I?
Generations are defined by birth year ranges: Gen Alpha (2013+), Gen Z (1997-2012), Millennials (1981-1996), Gen X (1965-1980), Baby Boomers (1946-1964), Silent Generation (1928-1945).
Can I calculate age from birth year?
Yes! Simply use the reverse formula: Current Year - Birth Year = Age. Subtract 1 if the birthday hasn't occurred yet this year.