Years to Seconds Converter

About the yr to s calculation

One year is exactly 31,556,952 seconds, so converting between them is a single multiplication. Enter any value above and the result updates as you type. The mean Gregorian year — 365.2425 days, which is why leap years exist. The SI base unit of time, defined by the radiation period of the caesium-133 atom.

Formula

s = yr × 31,556,952

1 yr = 31,556,952 s
1 s = 3.1689e-8 yr

Worked example

To convert 1 yr, multiply by 31,556,952: 1 × 31,556,952 = 31,556,952 s.

Frequently asked questions

How many seconds are in a year?

There are 31,556,952 seconds in one year. To convert any amount, multiply the number of years by 31,556,952.

How do I convert seconds back to years?

Divide instead of multiplying, or equivalently multiply by 3.1689e-8. One second is 3.1689e-8 years.

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?

Years: the mean Gregorian year — 365.2425 days, which is why leap years exist. Seconds: the SI base unit of time, defined by the radiation period of the caesium-133 atom.

Sources

• NIST Special Publication 811 — Guide for the Use of the International System of Units