In 1 centuries there are 3,155,695,200 seconds. Meanwhile in 1 seconds there are 3.16887e-10 centuries. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Seconds to Centuries calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert centuries to seconds, break the time down step by step using standard time units.
Formula (365-day years):
seconds = centuries × 100 × 365 × 24 × 60 × 60
So, 1 century = 3,153,600,000 seconds
Formula (365.2425-day years, more accurate):
seconds = centuries × 100 × 365.2425 × 24 × 60 × 60
So, 1 century ≈ 3,155,695,200 seconds
Tip: If you need a quick century to seconds conversion, use the 365-day result. If you want a closer match to calendar time, use 365.2425 days per year.
A century is 100 years. The exact number of seconds depends on which years you count.
Use this formula:
seconds = centuries × 100 × days per year × 24 × 60 × 60
If you want a simple average that accounts for leap years, use 365.25 for days per year.
A common estimate uses the average year length of 365.25 days.
1 century = 3,155,760,000 seconds
This works well for most math and time conversions.
Leap years add one extra day about every four years. Over 100 years, that adds about 25 extra days. Those extra days add seconds, so the total rises.
Each extra day adds 86,400 seconds.
If you treat every year as 365 days:
1 century = 100 × 365 × 86,400 = 3,153,600,000 seconds
This is a clean number, but it’s less accurate.
Using the 365.25-day average:
2 centuries = 2 × 3,155,760,000 = 6,311,520,000 seconds
Using 365 days per year:
2 centuries = 6,307,200,000 seconds
Half a century is 50 years.
Using the 365.25-day average:
0.5 centuries = 1,577,880,000 seconds
Using 365 days per year:
0.5 centuries = 1,576,800,000 seconds
Reverse the steps:
centuries = seconds ÷ (100 × days per year × 86,400)
If you want a general estimate, use 365.25 days per year.
Yes, a century is always 100 years by definition. What changes is how many days those years contain, due to leap-year rules.
Yes, in the Gregorian calendar, not every year ending in 00 is a leap year.
So 2000 was a leap year, but 1900 was not. Over long spans, this slightly changes the total seconds.
Accuracy depends on what “century” means in your case.
Using the 365.25-day average:
3,155,760,000 seconds = 3.15576 × 10^9 seconds
Using 365 days per year:
3,153,600,000 seconds = 3.1536 × 10^9 seconds
You still need a year length to connect centuries to seconds. Time units don’t line up cleanly without picking a rule for days per year (365, 365.25, or an exact calendar count).
The Calculate Box tool to convert centuries to seconds uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a centuries value in the box and have it instantly converted to seconds.