About the s to yr calculation
One second is exactly 3.1689e-8 years, so converting between them is a single multiplication. Enter any value above and the result updates as you type. The SI base unit of time, defined by the radiation period of the caesium-133 atom. The mean Gregorian year — 365.2425 days, which is why leap years exist.
Formula
yr = s × 3.1689e-8
1 s = 3.1689e-8 yr
1 yr = 31,556,952 sWorked example
To convert 3,600 s, multiply by 3.1689e-8: 3,600 × 3.1689e-8 = 0.00011408 yr.
Frequently asked questions
How many years are in a second?
There are 3.1689e-8 years in one second. To convert any amount, multiply the number of seconds by 3.1689e-8.
How do I convert years back to seconds?
Divide instead of multiplying, or equivalently multiply by 31,556,952. One year is 31,556,952 seconds.
Is this conversion exact?
For seconds through weeks, yes — they are fixed multiples. The year is the mean Gregorian year of 365.2425 days, which is an average rather than the length of any particular calendar year.
Where is each of these units used?
Seconds: the SI base unit of time, defined by the radiation period of the caesium-133 atom. Years: the mean Gregorian year — 365.2425 days, which is why leap years exist.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units