What this calculator does
How many seconds in a year comes out to 31,536,000 for an ordinary 365-day year, a number that comes up in trivia, coding exercises and rough back-of-envelope calculations. A leap year, with its extra day, adds another 86,400 seconds on top of that.
This calculator works out seconds in a year for a common year (365 days), a leap year (366 days), or an average calendar year (365.25 days, which accounts for the leap year that occurs roughly every four years), and scales the result for any number of years entered.
The formula
Seconds in a year is days in that year multiplied by 24 hours, multiplied by 60 minutes, multiplied by 60 seconds, or equivalently the day count multiplied by 86,400. For a chosen number of years, the day count is multiplied by that number of years first, then converted the same way.
| Term | Meaning |
|---|---|
| Common year | A standard calendar year of 365 days, the length in three years out of every four. |
| Leap year | A calendar year with an extra day, 366 days, occurring roughly every four years to keep the calendar aligned with the solar year. |
| Average calendar year | 365.25 days, the long-run average length of a year once leap years are accounted for. |
The inputs explained
| Field | What to enter |
|---|---|
| Number of years | The number of years to convert. Defaults to 1. |
| Year length | Whether to use a common (365-day), leap (366-day) or long-run average (365.25-day) year length. |
When to use it
Checking how many seconds in a year, exactly
A quick reference figure, 31,536,000 seconds for an ordinary year, is a common trivia answer and a useful way to frame a large duration in more familiar terms.
Working out seconds across a multi-year period
An uptime target, a project timeline or an age in years converts to a total seconds figure by scaling the per-year figure by the number of years.
Sizing a rate given in "per second" against an annual total
A process running continuously at a fixed rate per second can be scaled up to an annual total by multiplying by the number of seconds in a year, using the average year length for a long-run figure.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Seconds in a year, for a range of year counts
A range of year counts, each converted to total seconds.
| Years | Seconds | Days |
|---|---|---|
| 1 | 31,536,000 | 365.00 |
| 2 | 63,072,000 | 730.00 |
| 5 | 157,680,000 | 1,825.00 |
| 10 | 315,360,000 | 3,650.00 |
| 18 | 567,648,000 | 6,570.00 |
| 100 | 3,153,600,000 | 36,500.00 |
Seconds in a year, by year type
One year, converted to seconds under each of the three year-length options.
| Year type | Seconds | Days |
|---|---|---|
| Common (365 days) | 31,536,000 | 365.00 |
| Leap (366 days) | 31,622,400 | 366.00 |
| Average (365.25 days) | 31,557,600 | 365.25 |
Questions
How many seconds are in a year?
31,536,000 seconds in an ordinary 365-day common year (365 × 24 × 60 × 60). A leap year has 86,400 more, at 31,622,400 seconds.
How many seconds in a leap year?
31,622,400 seconds, since a leap year has 366 days rather than 365, an extra 86,400 seconds (one full day).
What is the average number of seconds in a year, accounting for leap years?
31,557,600 seconds, using the long-run average year length of 365.25 days.
How many seconds in 1 year compared to a minute or hour?
A year has 31,536,000 seconds, which is 525,600 minutes or 8,760 hours for an ordinary 365-day year; all three figures scale from the same underlying day count.
For the same period expressed in minutes, see the minutes in a year calculator. For the full time unit ladder from seconds to centuries, see the time converter.