Quick facts if you are 40
| Born in | 1985 or 1986 |
| Generation | The Millennials (Generation Y) |
| Chinese zodiac | Ox (1985) or Tiger (1986) |
| Days old (approximately) | 14,610 to 14,974 |
How to work it out
Subtract your age from the current year: 2026 − 40 = 1986. That is your birth year if your birthday has already happened this year. If it hasn’t, subtract one more year: 1985. The same rule works for any age, and you can check the result the other way round with our born in 1986 page.
Milestones
Milestones you have already reached:
- 16 (2001 or 2002): Full driver’s license possible in many US states
- 18 (2003 or 2004): Voting age in US elections
- 21 (2006 or 2007): Legal drinking age in the US
- 25 (2010 or 2011): Car rental usually without a young-driver fee
- 26 (2011 or 2012): Coverage on a parent’s health plan ends (Affordable Care Act)
- 35 (2020 or 2021): Old enough to be President of the United States
Milestones still ahead:
- 62 (2047 or 2048): Earliest age to claim (reduced) Social Security benefits
- 65 (2050 or 2051): Medicare eligibility
If you were born in 1986, your Social Security full retirement age is 67; for 1985 it is 67.
Frequently asked questions
If I’m 40, what year will I turn 50?
In 2036 if your birthday has passed this year, otherwise in 2035.
What year did I turn 18 if I’m 40?
In 2004 if your birthday has passed this year, otherwise in 2003.