How many seconds in a year
How many seconds in a year: a 365-day year is 31,536,000 seconds, the Gregorian average year this converter uses is 31,556,952, and pi times ten million is within half a percent.
In seconds
- Conversion factor An average: a year here is the Gregorian 365.2425 days and a month one twelfth of that.
- 1 year = 31,556,952 seconds
- In every unit
- 3.1557e10 ms 31,556,952 s 525,949 min 8,765.8 h 365.24 day 52.178 week 12 month 1 year
- As hours and minutes
- 8765:49
- 7.25 decimal hours Multiply the fractional part by 60: 0.25 x 60 = 15 minutes.
- 7 hours 15 minutes (7:15)
- And the other way
- 7:15 is 7.25 decimal hours
- Minutes that convert cleanly
- 15 = 0.25, 30 = 0.50, 45 = 0.75
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 0 | 0 | 30 | 0.5 |
| 5 | 0.0833 | 35 | 0.5833 |
| 10 | 0.1667 | 40 | 0.6667 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.3333 | 50 | 0.8333 |
| 25 | 0.4167 | 55 | 0.9167 |
How the Time Converter works
One year is 31,556,952 seconds here: the Gregorian average of 365.2425 days, times 86,400 seconds a day. Three figures are in common use and each is correct for something. 31,536,000 is a 365-day year, which is what a program counting calendar days uses. 31,556,952 is the Gregorian average. 31,557,600 is the Julian year of exactly 365.25 days, which astronomers define as a unit and which the light-year is built on. They differ by at most 21,600 seconds, or six hours.
Worked through: 0.5 year x 31,556,952 = 15,778,476 s.
Going the other way, one second is 3.168873851e-8 years.
For mental arithmetic: Pi times ten million: 31.4 million, within half a percent.
The approximation worth knowing is that a year is about pi times ten million seconds: 31,415,927, within half a percent of the average, and physicists use it for back-of-envelope work because it is impossible to forget. What this converter cannot model is the leap second. Between 1972 and 2016, 27 of them were added to UTC to keep clocks in step with the Earth's slightly irregular rotation, so some years were a second longer than their day count implies. Unix time ignores them (every Unix day is exactly 86,400 seconds), and in 2022 the General Conference on Weights and Measures voted to stop adding them by 2035. For a duration measured in years, a second is far below the precision of the question.
Precision is worth matching to the input. A measurement given as 0.001 year carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.
Time Converter FAQ
How many seconds are in a year?
31,556,952. One year is 31,556,952 seconds here: the Gregorian average of 365.2425 days, times 86,400 seconds a day. Three figures are in common use and each is correct for something. 31,536,000 is a 365-day year, which is what a program counting calendar days uses. 31,556,952 is the Gregorian average. 31,557,600 is the Julian year of exactly 365.25 days, which astronomers define as a unit and which the light-year is built on. They differ by at most 21,600 seconds, or six hours.
What is 1 year in seconds?
31,556,952 s. Multiply by 31,556,952: 0.5 year x 31,556,952 = 15,778,476 s.
How do I convert seconds back to years?
Divide by 31,556,952, or equivalently multiply by 3.1688739e-8. One second is 3.1688739e-8 years. The two factors are reciprocals, so you only need to remember one of them.
Is there a quick way to do this in my head?
Pi times ten million: 31.4 million, within half a percent. It is close enough for everyday use.
More from the Time Converter
- years to days
- years to hours
- years to weeks
- days to years
- minutes to seconds
- seconds to minutes
- seconds to milliseconds
- milliseconds to seconds