In 1 seconds there are 3.16887e-9 decades. Meanwhile in 1 decades there are 315,569,520 seconds. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Decades to Seconds calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert seconds to decades, divide the number of seconds by the seconds in one decade.
Formula (365-day year):decades = seconds ÷ 315,360,000
Quick example:
For best accuracy, pick the year length you need, then use the same value each time you convert seconds to decades.
A decade is often treated as 10 years. The exact number of seconds depends on leap years.
Most 10-year spans include 2 or 3 leap years.
The count changes because not every year has the same number of days. A leap year adds one extra day (February 29). That adds 86,400 seconds to the total for that year.
Time spans that cross leap years will have more seconds than spans that don’t.
Convert seconds to years, then divide by 10.
Using 365.25 days per year gives a solid average for long periods.
Ten years equals 315,360,000 seconds if each year has 365 days.
If the 10-year span includes leap years, add 86,400 seconds per leap year.
Yes, a decade is 10 years. The only debate is about decade labels in calendars, not the length. The length stays 10 years, but the seconds in those 10 years can vary due to leap years.
For many uses, an average year length works well:
This value matches the common leap-year pattern over long time spans.
Seconds per year set the base for seconds per decade.
A decade is the sum of 10 years, so the mix of common and leap years decides the final total.
Yes, if you accept an estimate. Use the average year length:
This gives a close answer for most large time spans.
It’s close, but it can drift.
Using 365 days per year ignores leap days, so the result can be off by:
That difference equals 172,800 to 259,200 seconds.
Leap years usually happen every 4 years. Some century years break the pattern:
This matters more over long periods, like several decades or centuries, because those skipped or kept leap days change the total seconds.
Use the average decade value:
For a rough conversion:
It’s not exact, but it’s easy and close enough for many real-life uses.
The Calculate Box tool to convert seconds to decades uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a seconds value in the box and have it instantly converted to decades.