Uses the average Gregorian year length in seconds (365.25 days × 24 hours × 3,600 seconds) for this duration conversion.
How it works
Dividing seconds by 31,557,600 gives years; multiplying years by that same figure gives seconds back.
What this does not include
This does not include exact calendar-date projection — for a precise date-based answer, use this site’s date calculators instead, which use real calendar arithmetic.
How to use this calculator
- Enter a value in either seconds or years — the other field fills in automatically.
Frequently asked questions
Why 31,557,600 seconds instead of exactly 31,536,000 (365 × 24 × 3,600)?
Because a calendar year averages 365.25 days once leap years are factored in — using exactly 365 days would drift out of sync with real years over time.
Is this the same average this site’s other duration converters use?
Yes — the same year-length figure underlies the hours-to-years and days-to-years conversions elsewhere on this site.
Where is this conversion most useful?
Rough duration estimates and general comparisons where an exact calendar date isn’t relevant, such as converting a very large number of seconds into a readable time span.
