In 1 seconds there are 3.16887e-10 centuries. Meanwhile in 1 centuries there are 3,155,695,200 seconds. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Centuries to Seconds calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert seconds to centuries, divide by the number of seconds in one century.
Formula (seconds to centuries):
[
\mathbf{centuries}=\frac{\mathbf{seconds}}{60 \times 60 \times 24 \times 365.25 \times 100}
]
Conversion factor:
[
\mathbf{1\ century}=3,155,760,000\ \mathbf{seconds}
]
Example:
[
\mathbf{1,000,000,000\ seconds} \div 3,155,760,000 \approx \mathbf{0.3169\ centuries}
]
Tip: If you already have years, convert years to centuries with:
[
\mathbf{centuries}=\frac{\mathbf{years}}{100}
]
A common year has 31,536,000 seconds. A century has 100 common years, so it has 3,153,600,000 seconds.
A leap year adds one extra day, which is 86,400 seconds. The exact total seconds in a given century can change based on how many leap years fall within it.
Seconds in a century depend on the count of leap years:
Formula:
Most 100-year spans include 24 or 25 leap years, based on where they start and end.
Leap years add time. Each leap year adds 86,400 seconds (one day). Over 100 years, that adds up fast, so using only 365 days per year can be off by several days.
If you need a close estimate, assume about 24 leap days per 100 years. For exact results, count the leap years in the exact date range.
If you treat each year as 365 days, then:
If you include leap years, add 86,400 seconds per leap year.
Using 365-day years:
That equals about 31.7 years. Leap years shift the result slightly.
A simple method uses the 365-day year:
If you need more precision, use a year length that fits your use (like including leap years) and convert based on the exact day count.
For a simple 365-day year:
If you want a closer real-world value, account for leap years in the date range and add 86,400 seconds for each leap day.
Yes. A century is always 100 years by definition. What changes is how many days those 100 years contain, due to leap years.
The Gregorian calendar uses this leap-year rule:
Because of that, some centuries have 24 leap years (like 1901 to 2000), while others can have 25 in many rolling 100-year spans that don’t line up with century-year boundaries.
It depends on where the 100-year window starts.
For example, a 100-year span that includes a year like 2000 (divisible by 400) includes that leap day. A span that includes 1900 (divisible by 100 but not 400) does not. Those rules change the leap-day count.
Using 365 days per year gives a clean estimate. Including leap years gives a truer count.
Over a century, the difference is usually:
That gap matters for timelines, logs, and date-based work.
Yes, but it’s an estimate unless you set rules.
If you don’t use a start date, most conversions assume:
That gives the standard value of 3,153,600,000 seconds per century.
For rough estimates:
You can divide seconds by 3.15 billion to get a quick century estimate, then adjust if you care about leap days.
The Calculate Box tool to convert seconds to centuries 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 centuries.