In 1 centuries there are 36,524.25 days. Meanwhile in 1 days there are 0.0000273791 centuries. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Days to Centuries calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert centuries to days, start with the core rule: 1 century = 100 years. Then convert years to days using the year type you want.
Quick formula (common estimate):
days = centuries × 100 × 365
Use this for a simple century-to-days conversion.
More accurate average (accounts for leap years):
days = centuries × 100 × 365.2425
This uses the average length of a year in the Gregorian calendar.
Exact range (depends on leap years in your dates):
days = centuries × 100 × 365 + leap days
Leap days vary based on the exact years included.
Examples
A century is 100 years. The number of days depends on how many leap years fall in that span. Using the common calendar average, a year is 365.2425 days, so a century is about 36,524.25 days.
If you use a simple 365-day year, then:
This is a rough estimate and ignores leap years.
A typical 100-year span has about 24 or 25 leap years, depending on where it starts and ends. That puts most centuries near:
The exact count changes with the calendar rules and the dates involved.
Leap years add extra days, but not every fourth year is a leap year. In the Gregorian calendar:
Because of the “100” and “400” rules, different centuries can have different day totals.
In the Gregorian calendar, most centuries have 36,524 days because the year ending in 00 is not a leap year (like 1900). Centuries that include a year divisible by 400 (like 2000) have 36,525 days.
The 20th century runs from 1901 to 2000. The year 2000 is a leap year (divisible by 400), so this century had 36,525 days.
The 21st century runs from 2001 to 2100. The year 2100 is not a leap year, so the full century will have 36,524 days. The number “so far” depends on today’s date.
Pick the level of accuracy you need:
Using the calendar average:
Using 365 days per year:
Common formulas are:
Use the average formula for a solid estimate across long time spans.
Yes. The count depends on which years are included. If your 100-year span includes a year like 2000, you may get one more day than a span that includes 1900 or 2100.
They can be either. You get an exact value only when you know the exact date range. If you only have “a century” without dates, the result is an estimate based on average year length.
Once you have the day count, multiply by 24:
Using common approaches:
The Calculate Box tool to convert centuries to days 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 days.